Several, almost all at once!
Create a Mall at Playfirst. Fun, similar to Build A Lot.
Hotel Mogul at Alawar. Haven't tried it yet, but I'm hoping! I've been waiting for a great hotel game. (Jane was pretty good, not great)
Jane's Zoo at Realore. I liked all but the last Jane game, and it sounds pretty good!
Also, all of the Wonderland games are discounted at $6.99 at Midnight Synergy!