While certainly not a definitive listing, the following are the pistols you are likely to encounter either new or used for either 25m Standard Pistol or Sport Pistol (now known as 25m Pistol). Be warned, the opinions of these pistols are my own and are likely to be biased, based on my own shooting experiences and of other shooters I know and trust (both of them).
Baikal: The IZH35 has to be the best value on the market for a no-frills and no nonsense target pistol that performs extremely well. It's not well finished, it isn't pretty, and the grips are a little agricultural (like many other Russian target guns) but it shoots remarkably well and would suit a beginner due to the low cost. Also has a high degree of reliability.
Benelli: There are two variants of this pistol, the MP95E, an economy version with plain grips and no-frills trigger, and the MP90S, the full target model. The MP95E can be upgraded at a later date. Generally a very reliable and user friendly pistol. Bore line is very low and grips are well designed. Most stories of unreliability stem from using ammo it just doesn’t like or lack of normal maintenance (cleaning). Suits a shooter who likes a long travel rolling trigger release. Its one weakness has been the trigger in the past, if you get a bad one it may be easier to buy a new trigger unit than try to persevere with a rough and erratic sear release.
FAS or Domino: Domino being the original model, the 602 was first released in the early 70s. A top loader magazine, it has a reputation for being very pointable and has won many titles around the world. Trigger is very much a roll, and may have as many as three distinct stages to it. The latest model is the FAS 607, introduced in the mid 1990s. Accuracy is excellent but reliability, especially with American ammunition, is questionable. Find the right ammunition and it will function flawlessly.
Feinwerkbau: The AW93 was many years in development, featuring an interesting anti-recoil system developed by a Russian designer many years ago. Trigger is quite crisp. Quality of manufacture is fantastic as you would expect, although in my experience recoil does not seem noticeably lessened.
Hammerli: Historically the 208 (named the 208S after 1988) has been the Sport Pistol of choice internationally since the 1960s. It's interesting that Erich Buljung still holds the world record in Standard Pistol with this gun (admittedly with a massive 200 gram barrel weight). It was popular with women because of its weight distribution (with its factory barrel weight its balance is well back in the hand). Obviously it is exceptionally accurate and well made.
The 280 was released in 1988 and was the first match gun to be have a carbon fiber frame. Time has proven the material has been durable, although I must admit I have been guilty of more than one quip about tupperware. It has a forward magazine, is quite bulky for the weight and has an apparently quite high bore line. For all this it has performed very well at international level. Just one thing to be wary of, never use a flame to blacken the sights.
Latest in ther Hammerli line is the SP20, released about 4 years ago. Apart from the lower frame this pistol returns to a much higher usage of metal construction. Like the 280 the magazine is forward of the trigger, but the bore line has been lowered. These are very popular in Europe and enjoying a great deal of success at the highest levels.
Morini: Morini's CM22M has been on the market for maybe three years now. Balance of the standard model is very nose heavy, since it features a full steel barrel shroud and the magazine is forward of the trigger. There is an aluminum shroud version available for ladies and juniors. Very high quality of manufacture, and in my experience was very reliable. Also had quite a crisp two stage trigger.
Pardini: These guns have been quite successful, and typically of Italian guns point very well. Again, the magazine is in front of the trigger, but because of its light construction is not notably nose heavy. Trigger tends towards a roll release, and they have a good reputation for reliability.
Unique: The DES69 was a great Club shooter's favorite in Australia. They were extremely reliable and well made, I believe from the early 70s until the mid 80s. Trigger is a two stage but extremely crisp on letoff.
The DES69U was basically an upgrade with a more adjustable trigger and more stylish barrel weights. With either of these models it is important not to let the barrel weight slide rearward until it contacts the slide pin, otherwise accuracy approaches that of a shotgun.
The DES96U is the latest model Unique. I honestly have not seen much of it in the International scene, although it is interesting that they "developed" a top-fed magazine similar to the 30-year old Domino system.
Walther: It is difficult to attempt to describe all the variants of the Walther GSP under one heading, as it has been in production in many forms for over 30 years. Very early models (1970 and before) had a tendency after a lot of use to crack the slide housing. This was beefed up in the early 70s and has never been a problem since. If buying one of these early models be aware that after market grip makers don't supply the grips that attach by two screws, one either side. This is a shame as the early models had some fairly unhelpful grips. In the 80s the grip fixture changed to a screw through the base of the grip. Triggers also changed somewhat around the same time. Early model triggers were almost a single stage but had a rolling release. The later models have a definite two stage trigger, but the letoff is far more crisp. Weight is very nose heavy, due to all-steel construction and the magazine being forward of the trigger unit, although there have been various versions with lighter barrels sold as junior models.
The KSP200 is in fact a tarted up version of the IZH35, featuring a more user-friendly (and prettier) laminated grip and a bolt hold-open button on the slide.
Being those guns which are made for general purpose target shooting but not specifically to ISSF rules. These can make good starter guns.
Beretta: The Model 76 was a target makeover of the pocket Model 70. Basically a longer barrel was transplanted on the same frame, and a set of crude adjustable sights fitted. All things considered they shoot very well, although the extra weight sometimes led to a little more than manufacturing tolerances in the barrel to frame fit.
The Model 89 was billed as a purpose-built target pistol. Alongside other European makes this is a little optimistic. Trigger adjustments are limited, balance and grip are so-so, resulting in it being listed down here. It is quite a reliable and accurate pistol however.
Browning: Back in the late 60s the Browning International was very well respected as a target pistol. Made in Belgium, it was quite a high quality item. A little difficult to find these days in good condition.
The Buckmark is Browning's current target offering. Basic and quite lightly constructed, but accurate and reliable. A slightly heavier barreled version is also available.
High Standard: These are excellent guns. They shoot very well, but most importantly are very user-friendly. The older models (pre-Texas) seem to be far more reliable, however.
Ruger: I'm afraid I'd consider the Mk 2 to be mostly a plinker. I see them a lot as club guns, and they are great for this as they encourage the new members to buy their own guns. Triggers are crude and they are a pig to take down for cleaning.
Smith & Wesson: The Model 41 has been in production since 1957, and I guess this says something. While I don't believe them to be quite as user-friendly or reliable as the older High Standards, they are still a great beginner's gun. They are also very well made.
The 2206 was advertised and sold as a target pistol. Why, I'm not sure. It was too light and for some reason I can't fathom it is very difficult to hold a group in the black. Not a first choice.
The 22S is the current target model (apart from the much higher Model 41). While a definite improvement over the 2206, it has had some history of breakages as "they don't build 'em like they used to".
These are the guns that had lots of potential but never made it. Mostly due to poor reliability or occasionally bad luck.
Britarms: A couple of versions of this pistol came out, starting in the mid 70s. Basically the idea was to build a better Domino. But they were plagued with reliability problems, and instead of sticking with a simple design the trigger was designed by a trade unionist (meaning it needed hours of labor by a specialist to tune it).
Patro: An Italian Walther lookalike. These were fantastic to shoot, if you could ever get through a match without malfunctioning out.