Provided your case is wide enough the best push/pin cooler i can think of is the Scythe Yasya.
It's huge and would be disastrous if not secured properly.
Another popular unit is the CM TX-3 which is an improvement over stock cooling and cheap. http://www.newegg.com/Product/Productcompare.aspx?Submi...
For the Yasya coolerguy has a good feedback review of the installation procedure.
I'm sure the guys here can tell you all about decent closed looped water coolers.
Not my thing.