I watch a series every here and then. Currently on ep.11 out of 26 of the Claymore series. So far very enjoyable. Some pretty good music/artwork, story seems fine so far, good enough characters. The action is actually entertaining.
Short reviews on things I've seen so far...
Yugioh Original - If you like the game and are somewhat leniently entertained it's worth checking out. The "enjoyment curve" is very short...if you like it you'll be enjoying yourself on the first episode.
Yugioh GX - I can't comment on the sub (unfortunately) but the dub isn't going to give you much.
Yugioh 5D's - The deck style (like in GX as well) is lamer but the story is darker and I actually find this series to be pretty enjoyable. Watch subbed.
Neon Genesis Evangelion - Yeah this was my first non-Yugioh anime (I'm going in chronological order here). I thought it was worth seeing but that's just me. There was one thing about it that made it kind of hard to watch but I would be spoiling it a little bit in spirit if I said it.
Elfen Lied - I would recommend seeing it. It's only 13 episodes and it will get your interest pretty fast. People usually talk about how violent it is but honestly I was expecting some kind of violence endurance test or something but it wasn't anything like that. It's just a story and it has some violent moments.
Gantz - I didn't really enjoy it that much personally, but there were some cool parts.
Code Geass (season 1 and 2) - I really liked this anime. Very entertaining from the first episode, good characters, etc. etc. I'd recommend it. My favorite next to Elfen Lied.
Shuffle! - The first anime I've seen that was entirely drama / social relationships etc. Kind of weird but it has a very cool daily life atmosphere to it. It would probably have been better to watch an episode every here and there.
Afro Samurai (season and movie thing) - I found this to be more violent than Elfen Lied. If you like following a cool character around as he kills stuff you will probably like this. The action was good but that was the main attraction.
Dears - Weird anime...can't say I got into it that much.
5 = average (this is a conservative scale)
Yugioh Original (dub) - 5/10
Yugioh GX (dub) - 2/10
Yugioh 5D's (sub) - 5.5/10
Neon Genesis Evangelion - 6.5/10
Elfen Lied - 9/10
Gantz - 3/10
Code Geass - 9/10
Shuffle! - 5/10
Afro Samurai - 5.5/10
Dears - 3.5/10