I really like watching commentaries on SC games. I started watching them a few weeks ago and I'm HOOKED.
Now I'm not a great RTS player. And I've never enjoyed watching sports on TV - basketball, football (English or otherwise) or even the way overhyped olympics - I just never cared.
But Starcraft is something I can somehow relate to. Especially Starcraft 2. myself, not being a good player, I see all sorts of strange tricks I wouldn't have seen otherwise.
Micromanagement tipping the results of battles in ways I wouldn't have even imagined. All kinds of strange tricks involved - it's mind-blowing sometimes, and really... really exciting.
The other thing is the commentators are very useful. They call out the strategy, which really helped a not-so-good player like me. you get some insight into their thought processes.
I knew Koreans were into Starcraft, but I didn't know they were THAT into it. I feel kinda sad now. As I see it, it doesn't matter who wins at Starcraft, I just like watching the game and could never imagine placing bets on it.