Um... Portnoy is one of the greatest showmen I've ever seen. Seriously, he stands up, he sits down, he throws his sticks around, he spits, he makes faces and shouts stuff at the audience, he's freakin' amazing and all that from behind the tether of a drumkit. Every single time I've seen DT live, his passion and enthusiasm and talent has been so visible it's given me spine tingles. He's incredible.
LaBrie doesn't seem particularly natural but he puts the effort in, as for the other guys I don't expect anything from Myung, Rudess always seems awesome and like he does the best he can while being stuck to a keyboard (and is good with the keytar) and I'm too busy watching Petrucci's hands to really notice what else he's doing. They're not the greatest band for putting on an amazing 'show' but I love watching them more than any other band out there.