I have Every light gun game available for the PS2, Saturn, NES, Master System and Genesis and it is true that the PS2 has hands down the best library with GunCon 1 & 2 and Konami Justifier compatibility, but the system I enjoy playing light gun games on the most is the MasterSystem. Although there are only 13 games (1 is 3-D as well), the Sega Master systems more responsive trigger and more accurate targeting makes it more fun for me. I found that none of the light gun games work properly on my 2 flat tube Sony Trinitron CRT TVs, but all work great on both my curved tube RCA and VGA monitor CRT.
I have a flat tube Trinitron KV32FS13 and I can confirm that it works with PS2 (GunCon 1 + 2), PS1 (GunCon 1), Genesis (Justifier), Master System (Light Phaser, using Genesis), and NES (Zapper).
PS2 is the king of light gun games, but PS1 is a close second. There are a bunch of patches for games that were Justifier compatible to work with the original GunCon. Since they're patched, the games won't easily run on a PS2, as I don't think Popstarter has good compatibility for light gun games, but I don't have experience with that, so someone may correct me.
With a swap disc or a modded PS1 with a GunCon 1, you can play:
Point Blank 1, 2, 3
Time Crisis
Time Crisis: Project Titan (excellent follow-up, BTW)
Gunfighter: The Legend of Jesse James (Spaghetti Western Time Crisis)
Elemental Gearbolt
Game Tengoku 2 (Shoot 'em up where player 1 controls the ship and player 2 uses a light gun.)
Judge Dredd
Maximum Force
Oh! Bakyuuun (AKA Ghoul Panic, the decent follow-up to Point Blank. English version is PAL release only, but I could not get the NTSC patch to work)
Project Horned Owl (GunCon patch)
Lethal Enforcers I + II (GunCon patch)
Crypt Killer (GunCon patch)
Die Hard Trilogy (GunCon patch)
Simple 1500 Series Vol. 24 - The Gun Shooting (In Japanese, I couldn't figure out how to get to level 2.)
Star Wars Rebel Assault II (GunCon patch worked, but Disc 1 crashed mid-game for me.)
Policenauts (GunCon and other patches seemed to work, but Disc 1 crashed before I got to a shooting segment, so I don't know if the GunCon patch truly worked or not)
I should mention that the GunCon patches don't always work with in-game calibration. A few of the games have to be played with adjusted sights, but it's probably still better than playing with the PS1 Justifier, given all the negative stuff I've heard about that lightgun's accuracy.