Depends where you live ??
Bang for buck
Deepcool gammaxx 300 & 400
212 evo
Raijintek themis
All spring to mind as good fairly budget options , will knock 15c or so off your current load temps.
The deepcool are straight 5 minute swap jobs using the stock and brackets.
The evo & themis (like most 120mm towers) require backplate removal.