Cooler Master Seidon is like $62 on OfficeDepot right now, don't know if its a sale or what but thats the price. I've been looking into getting one myself.
What CPU are you using? How much do you want to overclock? Are you looking for a closed loop solution like @Heaven suggested? Corsair makes pretty good closed loop water coolers. If you're looking for a more customizable open loop system, you can get something like this XSPC 240 kit.
I personally use a Corsair H100i for the simplicity and it works great.