Which cell phone/plan should I get?

I’m trying to decide between Verizon’s LG enV3 and their $60/month plan (450 minutes+unlimited texting) or AT&T’s iPhone 3GS and their $90/month plan (450 minutes+unlimited data+unlimited texting). In general, how good is each provider’s service? Also, is the iPhone 3GS worth the $90/month? Paying off the bills isn’t exactly the problem, but if AT&T has bad service or the iPhone simply isn’t worth it, then the enV3 would be my fallback plan.