I am looking for a great looking CPU cooler under 50, and I like red and black! I am willing to spend more if it looks cool. I am going to overclock my i7 4700K. Maybe 4.6-8 GHz or so. If there is a water cooler, I would spend 120 or less on it.
Well, you can expect a clock between 4.2-4.4 ghz with a cooler master 212 evo which can be had around 30$ish. If you want the 4.6-4.8 ghz overclock - and provided you got a good i7 chip - you should either get the noctua NH-D14, or a corsair water cooler. If you have a small case - water cooled is probably your best option (both the noctua and the CM are pretty dang big).
In between those options there are tons of OK coolers, but depending on how good your i7 is - it may or may not be worth the money.
In my personal opinion either get the CM 212 EVO, or go high end for the other options.