Personally, I like Spaz better, but Jazz's helicopters ears are useful sometimes in wide-open levels. Jazz looks cooler, though, because of how his colors are used. Both are good choices. As for Lori, I haven't played her tons, so I can't pass judgement, but she's a lot like Jazz except with a semi-sidekick instead of uppercut. She's OK in some situations, but the copter bug gets annoying because battle1 is used so much.