Marth's, Toon Link's, Ike's Link's, Captain Falcon's, and Ganon[dorf]'s can be dodged with a mere roll, or with Marth a shield.
I gotta go with either Donkey Kong, Bowser, Wario, or Yoshi. Donkey's Kong's when done perfectly is like a instant KO, PERIOD! (look at a post on the previous page) Bowser's is good, but only in Gimpyfish's hands. Actually, Bowser's is the best Final smash [in Gimpyfish's hands]. Everyone I've seen doing Wario's final smash sucks, and can't even control him. I see a lot of potential in it. With Yoshi's, I see a lot of my fellow spammers, and people with perfect aim making it a deadly weapon.
Edit: Samus' is pretty good as well. And the Landmaster. More proof Sakurai is biased towards Star Fox.
Anyways, the characters with the best Final Smashes in my opinion are:
1. Bowser
2. Donkey Kong
3. Samus
4. Yoshi
5. Wario
Watch me either be totally right, or completely wrong.