They're a quick and interesting way to get into figures-based tabletop gaming, and I already own a pile of Mechwarrior and some Indy HeroClix (for the 2000AD characters!). I find the rules and backgrounds interesting, and the quality of the models has improved dramatically over time (and unlike jaq, I don't have the patience to paint minatures!).
A recent arival in their range has been Shadowrun Duels - a game using much larger, more detailed, figures, and elements from FASA's classic fantasy/cyberpunk crossover Shadowrun role playing background.
I've been looking at these for a while, and finally succumbed and bought my first figure yesterday. Silver Max is a dwarf rigger, a tech hacker character. As the blurb on the WizKids' Shadowrun site says - "So he’s short . . . he’s got tech." I like that attitude.