I used to have a list of my favorite anime endings, but I don't know what I did with that list.
I'd say my all-time favorite anime ending is Maison Ikkoku. That was an extremely satisfying ending and worked out perfectly.
Hana Yori Dango had a great ending too. One thing that I loved about it was that even when I watched up to the middle of the last episode I still didn't know where they were going to go with it. That was a funny and amusing ending.
El Hazard First OVA had a very nice ending.
I really liked the ending of the Kakyuusei TV series. It was very touching and sweet.
As for my favorite ending from the past year of anime, I might have liked the Midori no Hibi ending the best. That was a nice one. And that was an anime-only storyline too.