I'm like that. It's always one series at a time and I just pick it up every once and a while.
Some I've watched:
Elfen Lied - Laughable in it's execution also very ecchi,
Suzumiya Haruhi no Yuutsu - Personal Favourite it's a slice-of-life mainly with a slew of other genres,
Code Geass - 2nd Favourite a mecha,
Spice & Wolf - Not sure what to say about it, it's very good though,
K-ON! - Another slice of life, I've heard it called generic moe... h8rs gon' h8,
Lucky Star - Comedy through and through in my top 5.. Don't let the intro put you off lol I would watch it for a year because of the intro,
Hellsing Ultimate - Better than Hellsing, a lot longer, a lot fewer.
Higurashi no Naku Koro ni-Kai/Rei- Great series Psyche, horror, comedy,
Trigun - Ending was meh, glad I watched it none the less, was pretty funny,
Witch Hunter Robin - Slow going like the next one but has some great visuals,
Jigoku Shoujo - Slow, same thing each episode for the most part but somehow still interesting.
If you haven't watched any of these give em a go. If you have, quote me and give your input. (Not trying to hijack the thread or anything..)
Taking note of that List posted.
Initial D - It's a cool looking car commercial lol,
Occult Academy - Really fun series, good subtle jokes,
Otaku no Video - Can be entertaining,
Fruit Basket - Not my cup of tea,
Moyashimon: Tales of Agriculture - Only show to feature crossdressing that I'd probably ever watch...