On what basis?! its just a buffy-shaped stamp with "CU" in it. for better or worse, that would rank their helmets somewhere up their with KSU.
There is absolutely nothing about the CU logo on the helmets that would in any way qualify it as the best in college football. period.
Everyone is going to have different standards but when "Best helmet" debates come up, it seems like there are two main factors: Unique and/or Tradition.
i like the tradition factor but i guess i'm biased as a Husker fan.
personally I would put Michigan's helmets at the top. though i don't know exactly what's going on with their helmets, they hit both unique and tradition IMO.
(below = including but not limited to...)
Purely traditional would be something like Notre Dame. also, Ohio State (especially with the buckeyes). Penn State and Nebraska, for example, are ultra simplicity backed with tradition. Even while Miami's unis can be outlandish, the helmet stays the same.
College football fans recognize the maroon/gold trojan, they recognize the "N", they recognize Miami's "U", its more meaning than just helmet logos. they all have legacies behind their simplicity. just as Penn State's helmets are boring but they are also Paterno.
CU's helmets may mean something to CU fans (great, good for them). but most outside of that fan base (and even some inside of it) couldn't give a rats @$$.