Play Super Meat Boy. Seriously. Its out on Xbox, maybe PS3 ( /shrug) and coming to PC via steam soon.
It's brutally hard, but it's so well designed that you don't even notice how many times you've failed, and when you do pull of a challenging level it is so damn rewarding. Speaking of levels, there is 5-6 worlds, each with 20 levels and each level has a 'dark' version that you can do one you've cleared the normal version under the par time. It's soundtrack is amazing as well, so good that on multiple occasions I've found myself humming along while I repeatedly fling myself into a pit of blade or lava (or salt...).
If you consider yourself a gamer you need to play SMB.
Warhammer 40,000: Dawn of War + the first two expansion packs (The Dark Crusade especially).
It probably remains my favourite RTS of all time - it borrows a lot from Starcraft and Warcraft, but I think it just does everything better. Brilliant, addictive gameplay, huge campaigns, with near infinite replay value in Dark Crusade, still a fairly good online community, great units, 7 playable races (if you do the sensible thing and avoid the third expansion Soulstorm which was a hurried mess and broke the game), and some of the most inventive & bloodiest kill animations you'll ever see in any game. The only game I've spent more time playing in the past 5 years than WoW, and I'm still in love.
Others have mentioned Company of Heroes, made by the same company, which is also incredible. It's just not got as fun a setting as DoW, though the online is probably a little better. Dawn of War 2 isn't anywhere near their level in my opinion, unfortunately, but has a very active community so it might be for you.