See that on the left. That's Travis Touchdown inhabiting the role of Francis in Left 4 Dead, as modded by DethKlan. DethKlan doesn't like Left 4 Dead 2, which is stupid, but they make an awesome mod, so they'll get a pass this time. You can download their work here.
Arguably even more fun is the mod on the right, which turns Team Fortress 2's Scout into a much sexier, stupider, maladjusted young man. The programmers at MechaWare really went all out on this one, creating a NMH-themed energy drink mod and baseball bat to go along with the Travis skin. All pretty awesome stuff. See video of it here, and grab the whole package here.
It would be great to see these mods sanctioned by Grasshopper and whoever (if anyone) brings No More Heroes to the PS3/360 in the USA and Europe. That way, they could given out as promotional DLC on the home console builds of L4D and TF 2. Travis Touchdown is a strange, unfamiliar figure to many PS3/360 owners, and getting to know him via these two very popular games could only work to raise consumer interest in the character.
I don't play L4D or Team Fortress 2 regularly, but if I had the option to play either of those games as Travis and the other killers from No More Heroes, I'd be tempted to rectify that situation.