IMO, Sonic's Final Smash is pretty lame. Sure, it's uber-powerful, it can clear the field and then some, and even n00bs can use it; but it isn't too hard to dodge. Unless you're fighting someone with excellent control and the skill and knowledge to utilize it, his FS doesn't really bother me.
For those who turn items off, I can understand. You are a serious brawler. Sometimes it's fun to play with no items on Final Destination and test your skills. And sometimes it's fun to use every item on Rainbow Cruise, spam anything remotely spammable, taunt for no apparent reason, and abuse items with glee.