City of Heroes: The game itself is a Super Hero themed MMORPG that has nothing to do with Steampunk. However, the possibilities are limitless with the wonderful Character Creation system. I have created 'Steampunk', aka Javier Tomas, a sort of Victorian Iron Man meets Captain America... only acting as an ordained Holy Warrior from the Catholic Church in a steam powered suit of battle armor, rejuvenated from beneath Vatican City where he rested as new threats of evil plague the world. His battle cry is, "Be gone Satan!" So far he can throw net/web grenades, drop Caltrops, shoot a blast of flame from his suit and klonk somebody over the head with his large Gauntlets. If I can capture a screenshot I shall.
Chrono Trigger: Hailed by some as the best RPG ever made, Chrono Trigger is a colorful, surprisingly emotional tale of a diverse team of adventurers battling against an ancient evil through multiple time periods. In the "Present" age of 1000 A.D., where our hero Crono hails from, we encounter a number of Steampunk stylings. First off, Crono's friend Lucca and her father Taban are genius inventors, creating Sight Scopes, Flame Throwers, Singing Robots, and a Rudimentary Teleportation Device just in time for the Millennial Faire. Also, Guardia Castle employs a steam-powered Dragon Tank as part of their special defense program. Chrono Trigger was released for the SNES in 1995, and was re-released as part of Final Fantasy Chronicles for the Playstation.
Arcanum: Steamworks and Magick Obscura: This is a dark and gritty RPG game for PC, shot in the same inclined overhead view as Diablo. But the surface is where the similarities end. Where Diablo is a Dungeon Crawler, this is a highly complex RPG with one of the most ingenious character creation systems ever devised. Note the steamworks nod in the title. This is a truly deliberate piece of Steampunk gaming. An integral part of the storyline is the battle between Magick and Technology in this Victorian-era world. The opening cinema shows the S.S. Zephyr (a zeppelin) coming under fire from Orcs piloting some very Da Vinci-an aeroplanes. Yes, I said Orcs. Unlike many examples of Ssteampunk, this one is heavily infused with fantasy elements. (However, they are subtle and work quite well. Your character can be any number of things, Gnomes, Half-Ogres, Elves, you name it. And yet, there is a very realistic quality to your choices. A Gnome, for example, looks like a short, fattish man with a large nose. The style for this game is very Victorian, and any steampunk fan will likely adore running around collecting gears, levers, and railroad spikes.) Never mind the clunky interface and the steep learning curve, go buy this game for 20 bucks on Amazon!
Syberia + Syberia II: Eccentric toy makers, automatons, wind-up trains and other Steampunk elements fill this dual attempt at reviving the adventure game series. While the first one was a decent game, the second is much more improved in all aspects. If you like exploring, solving puzzles and talking to automated life-sized toys, give these games a look-see.
the Thief series: Before snakes were solid, before the cell was splintered, before there were six rainbows, before... the Tenchu games (give me a break)... the first person "sneaker" game Thief was breaking new ground on PCs everywhere. Stealth was suddenly deemed more important than gunning down all opposition. You play as a hooded Thief during the Victorian Age, scampering to and fro with your blackjack and crossbow. In the second game, The Age of Metal, the plot centers on some up-to-no-good Hammerists, or Mechanists. You can guess there will be some good Steampunking! From gadgets like mechanical eyes to enemies like some large golden robot guards, the world of Thief is imbued with Victorian Era science fiction technology. A third game is in the works...