Honestly, I'm not too fond of Arrogant Bastard. Some people love it... probably not the one I'd try first, though.
Sam Adams is a decent bet, if you're trying to find something good at the grocery store. It's not nearly as good in bottles as it is on tap, though.
You mentioned Belgians, etc. For me, Belgians were definitely an acquired taste. I have a bit of a natural aversion to sweetness or sourness in beer. I've learned to love Belgians, but for the most part, they're either a tad sweet or sour, and it took me a while. I'd start with something more middle-of-the-road first.
Same with hops. If I'd started with a double IPA or something, I probably would not have been able to drink it. (Now I absolutely love super-hoppy beers.)
A few you might like that aren't really "extreme" in any sense are Sam Adams Boston Lager, Bass, Guinness (probably want to try Guinness Draught first, rather than Guinness Extra Stout), Sierra Nevada Pale Ale... Anything labeled "amber ale" or "American pale ale" is probably pretty middle-of-the-road.
Then you can learn whether you tend to like malty, hoppy, sweet, etc., and start trying some that have more of those characteristics.
I'm sure I've missed some great "starter" beers, but just off the top of my head, those aren't bad choices.