Buck, and specifically the Buck 119.
Not that people don't know about it, but some here equate Buck with cheap, practically worthless knives that they'd never consider putting in their pocket or on their belt.
As an example, ask this forum if the 119 would do fine for a camp knife and you're liable to get 500 answers saying "No way, it's not a full tang, it can't baton, it's only 420HC, light use only, I wouldn't depend on it as my only blade" and another 100 saying "It'll be fine, and for $60.00 it's a great deal". Then when you talk to someone who's only knife is a Buck 119 you inevitably hear something along the lines of "Works great, never let me down, stays sharp, tough as nails".
So in this community, Buck to some extent is underrated, and the Buck 119 is entirely underrated.