Crosby is the better player. It is close, and it is incredible how both have managed to stay playing at a high level for 15 years.
Crosby finished top 3 in Hart voting 7 (2-4-1) times. Ovechkin finished top 3 (3-2-0) in Hart voting 5 times. Both have 3 Pearson Awards (I don't know if voting results even exist). Crosby is slightly ahead in Hart Trophy Shares (500 vs. 412).
Crosby's top 5 point finishes: 1, 1, 2, 2, 3, 3, 3, 3, 5. A total of 9 times top 5 in scoring (this is excluding his 10-11 season)
Ovechkin's top 5 point finishes: 1, 2, 3, 3, 4, 4. A total of 6 times top 5 in scoring.
Ovechkin is clearly the better goal-scorer. Crosby is clearly the better playmaker.
Crosby has generally played on better teams, but has also generally been the better playoff performer. Both have their playoff warts, but Crosby's ability to climb to 7th all time in playoff points, mostly in a low-scoring era, is phenomenal. Crosby will likely climb to 5th all time in playoff points, with an outside chance at 4th. Ovechkin's 2007-2010 playoff dominance gets overshadowed by poor team performance.
Neither have excellent international careers, though that may speak more to their era than anything. Forwards just don't dominate international hockey post-Gretzky.
Crosby has the second most post-1968 AS finishes of any centre behind Gretzky with a result of (4-4-2).
Ovechkin has by far the highest post-1968 AS finishes of any LW with a result of (7-2-3). Obviously comes with the huge caveat of difference in position competition.
I think both are top 10 forwards of all-time, with limited ability to move up unless they return to peak scoring/Hart form, or someone put together more legendary playoff runs.