Arcanum was great, played it over and over. Variety of different character choices and a divergent plot path made for fair replayability despite how badly it's aged. Rise of Legends was also superlative, the RTS action being fun as well as the Risk Board campaign map. A lot of Steampunk in games seems to be Tech Vs Magic. I'm not sure where the idea came from, but I like it. As far as MMORPGs are concerned, there is a little Korean number called Neosteam. Atlus has the rights to it in the western world, it's free and fairly engrossing (For a MMORPG anyway.) though I tired of it after a month of fairly intense grinding.
A really awesome looking game called Edge of Twighlight was coming out, developed by the Australian studio Fuzzyeyes, though it seems it vaporwared before we got what seemed to be a post apocalyptic Steampunk 3rd person adventure. The main character had a blunderbuss as big as his torso with an axe blade underneath. I am dismayed.
Fear not, however. Studio Whitemoondreams has got ahold of the Warmachine license and is producing some sort of game based around Privateer Press' award winning tabletop miniatures property as we speak. The basic premise is a fantasy world where wars are waged by giant steam powered robots who beat the hell out of each other, controlled by battlemages called Warcasters who use steampunk technology mixed with magic to power all kinds of weapons and war engines. (As a player of the miniatures game, I am cautiously optimistic.)
Previously, the now defunct Headfirst games had the Warmachine license and were producing an RPG set in the Warmachine world, but it vaporwared with Headfirst's collapse. They also had another Steampunk license, and were making a game set in the Deadlands universe, an alternate history wild west filled with supernatural horror and weird science.
Never played them, but the Iron Grip series of mods and conversions seem to be WWII style combat only with Steampunk armour, weapons and vehicles. The concept art they got done was incredibly good, but I heard the actual mods were mediocre. They are doing some king of Beta or something for a game at the moment. I should probably look into that.
Well, there you are. I was watching ZP and saw Steampunk in the sidebar so I thought I should sign up, drop in and talk a bunch. I had to restrain myself when I heard someone mention Bioshock, but I'm calm again now.