Which CPU cooler should i buy (2600k)

Thermaltake frio i believe

You could try water cooling (a full-blown water cooling solution, rather than a pre-built loop) for the ultimate in cooling.

If you want air cooling, then I'd suggest Noctua D14 - it's a seriously powerful air cooler.

Both of these are $80  . I think i might just go with this XIGMATEK LOKI SD963 92mm HYPRO Bearing CPU Cooler, cause its cheap and it seems like it works for what i need.

Cooler Master Hyper 212 series works great.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I have a i5 2500K @ 4.2 and 1.33V. Runs 3degrees C above ambient at idle. 20 deg. C rise at full load.
*EDIT*
I Lied , 1.29V. Runs 7 degrees C above ambient at idle. 34 deg. C rise at full load.
30 Deg C Idle, 57 Deg C Load.

sandy bridge doesnt give out much heat so noise should be your main concern in your new buy, the be quiet dark rock pro/advanced is cool and quiet plus i think its in your budget

CM 212 Evo is the best air cooler for under $40 imo.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

What is the difference between the Plus and the Evo?

Evo has more copper exposed that is touching the cpu, so better cooling.

The EVO has a direct contact base,improved fin design,and quieter fan. = an improved version of the excellent 212+.
Either unit can handle a 2600K @ 4.5GHz no problem.

I think ill go with the EVO. Should work fine. Thanks for responses