OBP is the most important individual offensive stat. You could argue that WAR encompasses more, and if I could only look at one stat when trying to pick players for my team it would probably be something cumulative like WAR, or at least RAR, or TBA, or RC/27. But in the real world, in which I can look at any number of stats as well as watch a player, the first stat I'd look at would be OBP. If you look at baseball history, OBP has always been the most critical stat in terms of scoring runs. More often than not the team that leads the league in runs also leads the league in OBP, and when they haven't they're almost always 2nd. Last year was only the 2nd time since 2000 in which the AL OBP leader (team) hasn't scored the most runs. Only reason I know that off the top of my head is because I've had this argument on the Orioles website before, and they happen to be a modern AL team. But the trend is universal. The more guys you get on base, the more chances you have to score runs, and the more runs you tend to score. It's not just on WIS that Tony Phillips was a better offensive player than Dave Kingman or Rob Deer. Power is nice, but if you can draw walks and get yourself on base you're contributing to your team's offense.