Love the sport, though I've watched the Japanese version way more than the American one.
It's helped me greatly to acclimatise to life in Japan, as when I moved here one of the biggest things I missed was the Villa. I needed to find some sort of substitute. Tried watching J-League soccer but it just got me pining for the English game so I gave baseball a go.
Hadn't ever watched a game before I got here so started off pretty clueless, but soon got the general idea and started to love the sport. Eventually chose the Tokyo Yakult Swallows as my team and they've proved a worthy Villa substitute, and my level of passion for them is approaching that of Villa.
That was seven years ago and I go to around 30-40 games a year and have been to a fair few away games too (Japanese fans travel to away games much the same as UK footy fans).
As for the sport itself, it's much more akin to a condensed game of cricket as a spectator sport, though I'm not a real fan of cricket. People go to the games to cheer the team, socialise with friends, drink a lot of beer, eat food and generally be merry.
I think, similarly to cricket, if you watch a short segment of a baseball game it comes across as deadly boring. But the overall ebb and flow of a game is fantastic. It's one of the few sports that's not over until it's over - I mean in footy, if a team has a 2-0 lead with 10 minutes to go, more often than not the game is effectively over. In baseball, unless you're really getting a beating, all it takes is a string of hits and you can come back into the game, even in the final inning.
Plus in Japan, draught beer is served at your seat by young girls with a keg of beer strapped to their back - this alone is worth a visit.