I'm biased, of course, but I think ND has the best-looking uniforms in college football, bar none. And since 'Spray mentioned Clemson's purple, as alternate uniforms go, ND's green is much better in that it fits in seamlessly with ND's basic uniform construct, unlike Clemson's purple.
A couple of points here as far as uniforms go:
1. Not a fan of any monochromatic combo, including (and I know I'm in the minority here) white-on-white. I like to see a little color in the uniforms, and white-on-white is just too bland for me. As for Penn State's uniforms, yes, they're iconic, but they're not my thing -- far too bland.
2. If a school has silver or gold, or some variation thereof, as a secondary color, the pants should ALWAYS be that color. Period, end of discussion, and not even open for debate.
3. Unless black is part of your school's official color scheme, you should never, ever wear black jerseys.
With that in mind, and keeping in mind Mgo's rule, here's my top five, fwiw (1 1/2 agree with Mgo).
#5. Texas.
One-half agreement with Mgo on this one. I'm going with the home uniforms only. I don't think there's a color more unique to a single college football team than is Texas' burnt orange.
#4. Washington
The classic purple-and-gold look, at least. Washington is a school that has been guilty of breaking two of my rules above -- the monochromatic purple-on-purple look, as well as the black jerseys look. The standard purple-and-gold look, though, is classic and even understated (not easy with that color combo), yet still eyecatching.
#3. Ohio State
Scarlet and grey is a stylish -- and unique (although Rutgers seems to be moving in that direction with the chrome helmets) combination. I also love the individual buckeyes on the helmet to denote big plays.
#2. Florida State
The other part of my agreement with Mgo. Unlike him, I never had a rooting interest in Florida State, but I always thought their garnet-and-gold uniforms were sharp. They would have made #1 on my list but for the squaring off (as opposed to rounding) of the top half of the number 3 on their uniforms. There's a reason I picked out a photo of E.J. Manuel.
#1. Michigan
It may be blasphemous for a ND fan to say anything complimentary about Michigan, but there is something about their uniforms. I know the stripes on the helmet were thieved from Princeton, but they're still cool. And the colors, while not identical to ND's, are close enough to have fooled my mother-in-law.