Honestly, I love mainstream anime because I get to enjoy it for a very long period of time without worrying about not being able to continue it, like you may get with other series. The only thing that these series tend to piss me off with is the fillers. I usually don't mind too much if the fillers work well with the story and they are not placed at cliff hangers and such. Also ... the flash backs can get irritating at times. I don't understand why we need to see the same flash back 10 - 20 damned times with in a 5 episode span XD. In case you are wondering, I am mainly talking about Naruto ... and sometimes Bleach. They are notorious for fillers really.
However, I watch just about anything and everything anime, it's just a matter of finding something I am in the mood for at the time. I typically enjoy watching subs more than dubs with very few exceptions. Japanese isn't my native language though, English is.
I also keep up with all the newest anime each season. I don't watch everything, but I do try to watch a good portion of the series that come out.