Here are my top 5:
1) Revolutionary Girl Utena - A modern fairy tale that touches on childhood dreams and the challenges and dark aspects of adulthood. Great story, fleshed out characters, beautiful animation, rocking soundtrack, and so many symbolic images and motifs used that actually contribute to the overall narrative. I always catch something new whenever I watch it. The movie is a re-telling of the show and it's very odd and confusing. Wouldn't recommend watching it without watching the show first.
2) Gankutsuo - It's a sci-fi retelling of The Count of Monte Cristo, told in the perspective Albert instead of the Count himself. It stays very true to the novel despite the changes, but the thing that everyone notes is the art style. Most of the characters, objects, and backgrounds are not filled with solid colors but with patterns. Sometimes it doesn't work well and looks bad, but most of the time it does and there are some scenes that simply look gorgeous. It's understandable if people don't like the artwork, but try to look past it and watch the show for the story it offers and it's quite the thrill ride.
3) Baccano! - Three stories told at once, with the series beginning with the ending of them and going backwards. It's a really odd setup, but it works well. It's not confusing to follow, the stories are all different, but the best part--the characters. Some of the funniest and most fucked up characters I've seen in an anime are here and it's a blast to watch them all interact with each other. Oh, and one of the best English dubs out there.
4) King of Braves GaoGaiGar - This is an older one, but dammit I love it. It has cyborgs, fairy kids, mechas with personality, unique ideas for enemies that reflect on negative aspects of people, and bad guys named after Italian food. Awesome! Before we had Gurren Laggan, we had this as our lavish love letter to the super robot genre, so if you liked that show give this one a shot. Admittedly it's very slow to start, but once you get past the first 12 episodes (out of 80+ if you count in the later installments, so not too bad in the long run) it immediately picks up and it's a blast to watch.
5) Death Note - you already mentioned this one, so nothing to say here.