Magic Online. If you enjoy Magic The Gathering, you will tolerate Magic Online. If any game with Magic's mechanics was put online, it would do quite poorly. Only because of Magic's 15-year history can a game with so many bugs and so many "OK/Cancel" dialog boxes be so sucessful. And yet, I have spent over $1000 playing this game. I have yet to see a head-to-head strategy game better than Magic Online. I'm "bsr Orion Purple" if you want a match.
World of Warcraft. I'm playing this partly out of fun and mostly out of requirement. WOW is a requirement for industry understanding, and until I have a level 60, 70, 80 character there are people who won't take my observations seriously. I have given up trying to fight this... now I fight against the Horde.
Sanctum. The second online CCG, after Chron X. The game takes place on a map, and the cards in your deck affect the action that takes place there. A decent fantasy world with an original take. (Yes, there are elves. But there are also Cyclops [Cyclopi?], Centaurs, 'Visions', Imps and many other fantasy critters.) Account name "Lurid", purchased from a friend a long time ago.
Astral Tournament. Decent little game. Plays like a CCG but is more of a strategy game that happens to use cards. You do not build a deck, but instead have access to all of your cards every turn (but you may not have the resources to play everything). My account name is Audera Blue.
Madden NFL 09 (Xbox 360). This might be my favorite version to feature online play. Rock-solid, proven, tuned and tested gameplay that matches the action you see on Sundays. Their online matching system could be improved, and the league structures are an afterthought -- after several years 'EA Sports World' still isn't where I'd like to see it. Despite that Madden is still Madden, and I will still buy it.
What I'm Playing Offline
Rock Band 2.
This game lets you be a rock star. What else is there to say? How about "Buy this now?" I have been a fan of Harmonix forever -- goting all the way back to their first games Frequency and Amplitude. Yes, you can play this game online. But the real fun is playing it with three friends in your living room.
Magic: the Gathering.
This game is the reason I started making games professionally. It is brilliant on so many levels. It seems likely that I will be playing this game 15 years from now.
Roshambo, or Rock Paper Scissors.
My daughter and I are getting a large amount of RPS play in these days. And, since every strategy game boils down to RPS anyways (heh), why not become a
master at this game? It is simple, balanced, and deceptively deep. My favorite strategy is Avalanche (Rock, Rock, Rock) but sometimes I go with Know Your Role (Rock, Paper, Rock).
What I'm No Longer Playing, But I Like Anyways...
City of Heroes. A MMORPG where you play a super hero trying to defend Paragon City. Even without being on a "roleplaying" server, people still spend the time making interesting little character histories. I enjoy that to no end.
Legacies LARP. A live-action roleplaying game? Really?
Yes, really. Legacies is a boffer-weapon fantasy adventure game, meaning if I want to kill a goblin with my sword I must actually cut him to pieces. Well, actually, "tag" him several times with latex weapons that look very much like swords.
These types of games, when done well, are the perfect mix of athletics, improvisation, strategy, politics and puzzle-solving. When done poorly, well... all tropes come from somewhere, right? Legacies is without question my geekiest fun. Emphasis on fun.
Dungeons & Dragons.
The 4th edition rules make this game great. Just don't call it a roleplaying game, OK? It is a tactical strategy wargame with fantasy
trappings. It is fun! I enjoy it a great deal! But if I wanted to actually roleplay, I'd play...