I like using Phamatik Poo (sic) and Numerology, soon to be NI Battery to basically trigger samples.
and
cycling74.com 's new MODE synth looks, so far so good, like it could be a nice drum synth but I am eagerly waiting on Logic 7's Ultrabeat synth. There are a bunch of people on KVR that sing praise for the BFD synth but I haven't tried it yet.