For me the main one that pops into mind is Gravitation. It and couple episodes of Loveless are the only two shōnen-ai animes I've ever seen, but I ended up really liking this to the point that I even read the manga too. I don't even remember why I started watching it, but the drama and dynamics between Shuichi and Eiri kept me hooked. Of course I'll never admit this and have on more than one occasion made fun of Gravitation with my friends, but somewhere deep in my closest is a box with all 12 manga volumes and the anime boxset lovingly packed away.

Hetalia is the other one that I've recently become pretty obsessed with but hide from others. Enough of my friends have seen the anime that I feel comfortable admitting that I like to watch it, but if anyone asks if I've read the web comic I pretend like I don't even know there is a web comic.

So yeah, please share your secret anime loves or better yet, any stories you may have about being caught or something. It'll be cool to read and who knows, you it may even inspire us to watch something we normally would not.

What else can I watch that is mindfucky like Lain?

Check out this blogger who writes his views on it here: http://holding-on-still.blogspot.com/2009/04/full-metal-panic-live-action-zac-efron.html

I liked FMP a lot, it was very good and funny, hopefully they don't ruin it(though it is a high probability) like they did to dragonball z(haven't watched the movie myself :\ so basing this on reviews i heard)What do you guys think on this? Zac doesn't look or seem like he would be a good sousuke.

Official site: http://www.haruhi.tv/

a.f.k.'s wonderful translation: http://a.scarywater.net/afk/

Oh and try to keep it on the more obscure level. i.e. no BLEACH, DEATH NOTE, NARUTO etc.
HERE GOES:

Mine was Planetes. I was at a used record store trying to find something new to watch. Everything was pretty much sold out, when I stumbled on this box set of Planetes. The cover wasn't much to look at, and the "Anime Legends" heading made it look even worse. The cover was some guy in an orange spacesuit desperately trying to grab a floating screw in space. I thought to myself at the time "That looks stupid."

I turned it over and read the back, which revealed it's an anime about "space garbage men." "Even more stupid." I chuckled to myself. However, I was desperate so I gave it a chance, and bought it. I took it home, and started to watch it, lo, and behold, IT became one of my most favorite anime EVER!

The story really posseses great drama and showcases humanistic love. It really posseses a message of anti discrimination (for any race, religion, etc.) without being preachy. What's amazing too is that they introduce a large number of characters, but each one is so thoroughly fleshed out, that they all even appear at the final climax. This show truly starts out as a story about space garbage men, and then surprisingly becomes something else much more deeper than that.

What do you suggest?