Tommy has always been the weakest protag for me. There's nothing sympathetic about him, which makes him very hard to relate to. He's just a bellowing psychopath and playing as him isn't fun.
Plus, he's a really weak pastiche of Scarface and other dull movie stereotypes. It's no wonder Ray Liotta distanced himself from the project afterwards. Screaming and shouting your way through a script can't be much fun, and the dialogue he had to scream and shout was pretty weak. It's because of this that I've only ever completed VC once. I've played countless hours of end-game, but he's such a one dimensional character that I just don't want to hear him.
Basically, a protag needs to be entertaining and fun to play as, otherwise it's a chore. That's why I really can't be bothered with Michael now. He turns into a dull, repetitive, up-his-own arse wanker - Tommy was that right from the outset. Sure, he's a 'badass', but that doesn't count for much when you can't stand to hear him talk.
Hands down, to this day, the mute is KING. Claude, we need you back, now more than ever.