Puella Magi Madoka Magica
Michiko to Hatchin
Clannad After Story
Anohana, although now that I rewatch it, I end up laughing when I get to the ending
Rinne no Lagrange
Air, both the anime and the movie
A Channel, it gave me a nice, fluffy feeling with its ending
Kyoukai Senjou no Horizon
Baccano! made me feel pretty damned good with it's awesomeness. Yeah, my butt totally hurt and my eyes and head felt weird from sitting there are and watching it all in one sitting, but I wouldn't have changed that experience for anything. That show was amazing and totally worth it. (Though, I don't think I'll be watching a series all at once again.)
Mawaru Penguindrum gave me that, everything-is-well-in-the-universe feel when I finished. You know what I mean, right? That totally content and peaceful feeling. I can't speak for the rest of the fanbase, but I was absolutely satisfied with how it ended. I loved it.
Red Garden is the only series that I've watched that made me want more IMMEDIATELY after I watched it. Sure, I've missed shows before, but there are few shows that I've actually watched from beginning to end more than once. And those few rewatches certainly didn't come right after the first. But for whatever reason, right after I finished Red Garden, I watched it all again. And again. And again. And again. I've never done that before. I guess it just really hits the right cord with me.
When I'm finishing a new favorite series, and the ending doesn't screw it up completely. I don't have to particularly like the end, as long as I can look back on the series and say it was great. Recently Mirai Nikki. Also Madoka Magica, Steins;Gate, Mawaru Penguindrum, Toradora, Clannad.
Neither of these series had particularly strong endings. Haibane was really corny (granted, my opinion) and Mushi-shi didn't have a legitimate conclusion. I'm curious how these last episodes marked you?
Those anime are for people who can hear sound of falling snowflakes and enjoy it. You must make your own reflections, if you want to understand them. Nobody will use your brain for you. That's all I can advise you.