Definitely Sammy. He's a WAY better singer and helped write much better songs too. Not to mention he's a nice guy. I saw him in concert one time in a fairly small venue and he took a break from playing when they needed to change stuff around or something and taught everyone how to make Cabo Wabo's on stage and then passed some around to the front row
He's just Cool(tm). Roth is a jerk (but, yes, he's more funny).