rush in the performance aspect of proficiency but no band is the best as they are all different grooves
My favorite band to see live is probably The Chariot.

As much hate as they seem to pick up around here, seeing Pierce the Veil is never a disappointment either. They play everything real close to the album, and have a good show to boot.
Tough one...from the bands I've seen...

Muse, Sufjan Stevens, Atmosphere, Oasis, Kasabian, Billy Talent, Death Cab For Cutie, Harvey Danger, Minus The Bear...

In no particular order...
in no specific order:
nine inch nails, black label society, rush, juas priest.
Black Veil Brides
Bullet For My Valentine
Asking Alexiandria
Avenged Sevenfold
Bring Me The Horizon
Miss May I
The Medic Droid
Quote by enraged_waffle
Tool. By far the best Ive seen.

yeah i saw a perfect circle open for nin. they were real good so tool was probly real good too.