Here's some suggestions if you're still into PS1 emulation.
- Silhouette Mirage -- it's a side-scroller from Treasure. Think Gunstar Heroes meets Ikaruga (even though Ikaruga came after this game), where you use various weapons (parasites in this case) and the game has dual-polarity element sorta like Ikaruga, but in Silhouette you can only damage enemies opposite of your element but you do have a shield that can deflect same-elemental attacks back at them. Originally it was on the Saturn but it got re-released on the PS1 and localized by Working Design (with some gameplay changes to make it harder than the Japanese version).
- Strider 1 and/or 2 -- both of them are on PS1, I doubt I need to explain this one.
Also this for PC games:
- Streets of Rage Remake -- a great fan-remake of the Streets of Rage series. It combines all the games into one, adds new gameplay elements, branching paths, multiple endings, customizable game settings, and nice set of remixed music from the series. Sega unfortunately gave the devs of this remake a cease-and-desist but the final version of this game is still floating around. I can PM you the link for it if you want.
- Kamui-- a personal favorite of mine and a great shoot 'em up. Imagine RayStorm done by Treasure. You control a fighter that can use a spread shoot, homing lightning, and a powerful lightning beam that cancels bullets. It's an old doujin PC shoot 'em up, but it's still fun after all these years. It's available on Desura and I think on Steam by now.
- Tyrian / Tyrian 2000 -- another oldie that loads of fun to play, and it's freeware to boot. You can customize your ship in the Story Mode (most of story stuff are in the Data Cubes you can collect, ) or the Arcade Mode with random power-ups. The game is kinda episodic, like some early FPSes, and there's about 3 episodes to play (more in the later versions). It's an old DOS game, but DOSBox can help and GOG.com has the game pre-packed with DOSbox and everything you need to run it easily on modern systems. It supports mouse controls and they're great.
- ETHER VAPOR Remaster -- an updated version of the 2007 doujin shooter ETHER VAPOR by Edelweiss. It's a shoot 'em up with changing perspectives and you are armed with three different weapons, each with their on basic and charged effects, that can help in certain situations. Has been localized by Nyu Media and it's up on Steam and Desura.
- Astebreed -- an even bigger and prettier ETHER VAPOR successor although it's easier to survive in this game than ETHER VAPOR (unless you're playing on Hard mode) but scoring is much trickier. It's on Steam and Playism.
- Fairy Bloom Freesia -- I guess you can call this part beat 'em up part tower defense since you play a fairy that can kick all kinds of ass to protect a forest from monsters and evil-doers that wishes to do harm to it. There's RPG elements in it as well that lets you level-up the fairy and give her new moves to learn. Also on Steam and Desura.
That's so far what I got on the top of my head.
-EDIT-
In case you were wondering about that poster and magazine that security guard from Metal Gear Rising has: those were done by the artist of Senran Kagura.