ANTS Profiler!
After i got the second prize on dotnetslackers contest, i finally got to try ANTS profiler. Before this time, i never thought i could use such products to know how my application is performing but after the first try i found it VERY useful. It helped me see which functions are taking the longest time to execute plus more functionality. for more information about this product check below link
ANTS Profiler By RedGate
Thank you Sonu for introducing me to Redgate company.