For me simplicity is the key.The titles post it turning into Raw V/S Smackdown had wierd control system & had to be taken somtime to actually get to know the correct manoverus.Here comes the pain was a very straight forward title with plenty of character option which had actually driven it to success.No wonder it had got a 9+ rating at gamespot.
Smackdown 2 on the other hand I have to agree was the best & most simplest title till date.That game was(& still is) a rage when it came out.The best thing about it was the graple moves which were dam simple to execute & finishers could be easily executed.Moreover there was plenty of room of customising a character & with a few mem card saves over the internet they had actually created some excellent replica's of RVD,Brock Lesnar,Hulk Hogan & Rey Mysterio.
It's not tough to map the controls onto a PC too.Heck I have played Smackdown 2 far more on the PC than I ever did on the PSone & with zero difficulty with the controls.So hope they make a PC version pretty soon.