The two most common from my travels have been Arkaos and Resolume. Arkaos has a fair bit of ill will amongst certain parts of the VJ community for a number of reasons, including the way they charge for their own bug fix revisions. Personally i dont like the program and i wouldnt purchase it. Resolume it what i have a bias for personally as i used it for some fun triggering video from my v-drums and explored it a little in a previous band. In the current live act im in our VJ has a Resolume based rig and it works well with live feed video and sync's tight enough to my MPC or MPD so we can trigger video and audio samples in sync... some nice stuff.
Im sure the VJ forums you can dig up on Google will usher in a whole new world of software recommendations, but these are the two i am familiar with
