HI

I am planning to buy a new Monitor, my budget is rather limited but I want to know I see resolution option in monitors, what will be the difference between 1366x768 and 1600x900 or 1920x1080 pixel monitor and for daily use and occassional gaming, which one is better. I see that 1366x768 are cheaper, so what is wrong in them , I see same size monitor with more than that resolution is quite costly compared 1366 x 768, so what is the benefit ?