There are no "best" settings, thats why there are so many to play with in emulators. It depends on many factors whether a game runs well in a emulator, also dont forget that emulators are far from perfect a lot of the time and use hacks themselves to get things working, not to mention every game is different and one may emulate 100% perfect and the next game you try with the exact same settings may look and run like absolute trash.
Then you get onto emulators like pcsx2 for PS2, that needs different emulator settings on a per game basis.
So to answer your question, no there is no site with "best" settings, as what may work for you may not work for me. It seems to me these days people are to scared to touch anything on there systems anymore. The emulator has options, your PC wont explode if you mess around with them to see what they do and if they help.