Solitaire Chess

I like to play solitaire chess and have access to an online database that contains millions of games. My question is whose games should I, an intermediate player, study? I've already studied Morphy's games but I would like to get away from his tactical style and play more positionally. Whose games and which openings would you suggest?

If you have a favorite opening system or systems, it would make sense to go through the games of the specialists in the opening. So, for French Defence, I'd study Korchnoi, for Petrov Defence - Kramnik, etc. You need to find out who the specialists are, though. And if you are playing something offbeat, such as the Grob or the Damiano (heaven forbid), it may be the time to change your opening repertoire.