Rts or fps PvP game that is at least decently popular and the PvP opponent being quite similar to that of AI?

Played many of popular PvP game before and as usual we all start with vs AI first and later dabbled with PvP and my opponent does feel similar to AI at first but very soon they don't feel similar to AI anymore and when I dislike what it has become I have to create a new account and replay again and repeat again and again everytime which I don't want that to happen.