I'm not really a flash game player but have dabbled a bit in the past. I usually found online flash games subject to too much delay which is frustrating and thus makes the game unenjoyable. Of course that could be due to my PC/bandwidth limitations at that time. Whenever I could, I would download the game and play standalone. This included poker/betting type games and some of the Japanese type sim games.
When I last looked there was an absolute plethora of flash game sites out there, each with specialised genres for your greater enjoyment, even adult specific.
Which games have you/are you playing? Might be interesting to provide some feedback here of your experiences and preferences.