I'm down to two active games from an average of about 20 since I joined this past May 28th: number 250 and 251 on my list.
I've played almost exclusively 4-6 player standard-sequential-escalating-unlimited on various maps.
I've plowed my way through 200 or so public games and then set up 50 or so private games, which means I've actually had a few go 13+ rounds.
So what's next?
Freestyle rocks, but the kind I like takes hot routings to the server, which I don't have, so I can't focus on those.
1vs.1 standards are fun, but not really challenging enough. I still might focus on those for a while.
No-cards I've never been into, but I could be talked into 100 games or so with the right group.
Doubles and Triples: meh...they're just 1vs1 with a new shirt. (although the whole cross-reinforcement thing is a fun twist)
Fixed-rate is ok, when I'm in the mood for more luck-variability, but forgive me for refusing to play those with a wide rank range of opponents. You know what happens when someone gets three mixed sets in nine rounds with a couple bonus-owns in each set? Game over.
Speed games? Nice but not great for escalating players who count on setting up board sweeps. Next rev. waiting.