CM Hyper 212X is a very good Air cooler. [MENTION=148045]anirbandd[/MENTION] - has i5-2400 and it serves him well afaik.
Since you didn't specify your budget so in case you are willing to spend more then take a look into the offerings from Noctua. Afaik one of their model priced around 5k is regarded as the best air cooler ever.
what are my options below 5K ? I want something just better than stock cooler and not top of the line cooler.
Have beenusing "Cooler Master Hyper 212X" for 6 months. in idle CPU temperature doesn't go above 43 degree!! (its an AMD FX 4300 no OC). Max temp reach is 51 degree in full CPU stress.