I'll go against the flow, with a decided vote AGAINST Snickers. Way too overdone! And Hershey is too.
My favorites are:
Cadbury
Reece
Twizzler ("The Twiz" haha)
Truffles
Smartie
Rocket
Goober
Wrigley
Twix
Heath
Mars (if he was the macho type!)
Rolo
And hey, I used to have a dog named Jelly Bean!
The only other additions I can think of:
Sweet-tart?
Airhead, or Warhead (if the personality fit, lol!)