I didn't forget stealth games because I haven't played any
what I did forget is roguelikes, elona is gdlk
Considering PC game sales usually make Beyond Good & Evil?, Deus Ex - can be played stealth if you want -, Dishonored, Ghost Recon, Hitman, Mark of the Ninja, Rainbow Six, Sniper Elite, Splinter Cell, Thief, and Velvet Assassin games dirt cheap... Pick a random one up one day. Older Metal Gear, Sly Cooper, and Tenchu games will be more difficult since they're not on PC, but on systems, mostly PS2, that might be trouble to get their games. For MGS and Sly Cooper, there's the HD collections on PS3 and Xbox 360 - not Sly Cooper since it's a Sony exclusive -, so whatever, but Tenchu's probably trickier. Also, if you've played Wind Waker and Phantom Hourglass?, you could consider those as technically stealth games with their stealth portions. Pretty sure Phantom Hourglass had more stealth sections than Wind Waker. Games that can be played stealth include the Assassin's Creed games - starting from around with Brotherhood wrecked everything and made them high profile killers -, the Crysis games, Fallout 3 and onward, the Far Cry games, The Elder Scroll series, though they're pretty bad and broken without mods, The Last of Us, sort of Mass Effect since there are stealth-based classes, so pretty much any (action) RPG with rouges, but it's not "stealth-stealth" like in Splinter Cell or Thief, Payday, Prince of Persia? - I know it has stealth sections, but I think it's more of a platformer -, the Tomb Raider reboot games, and Warframe. Also, horror games, but that's more of GTFO and curling up into a ball waiting for the monsters to go away.