The only ones that I had any particular interest in were "Middle East Sniper" and "Waifu Hell".
For the latter, it's a crappy small map with four portals and infinitely spawning enemies that always seem to come out from the direction you're not looking at that given point in time, leading to a frustrating kill from being shot in the back.
For the former, however, while it did grow monotonous quickly, I found out something intriguing about it. Normally, when you scope in and fire your shots at long ranges, you have to account for wind and gravity in your shots...
however, if you fire the gun while you're
not scoped in, your bullets travel a great deal faster (for no reason whatsoever), making the outside forces working against your bullet minimal at best. This is good because there's a large building to the very far left of the main tower where the
naked babes filthy terrorists' heads take up no more than a few pixels on your screen, and usually congregate in groups of two or three at a time—scoping in, you'll never be able to hit them; adjusting your view and hip-firing your rifle while holding Shift, however, should allow you to just barely hit them about 20% of the time, granting you a massive point bonus from the sheer distance alone (
the game's arbitrary distance calculator has them measured out to nearly two kilometers from your starting position).
