Clannad. Steins;Gate. Guilty Crown. Fate Stay/Night and Zero. Nichijou. Nichibros. Toradora. Nodame Cantabile. Natsume. Penguindrum. Gosick. FLCL. I can just go on.

EDIT: I missed Madoka even though that's my avatar!

Man I find these lists pointless. It's down to personal tastes at the end of the day.

Madoka was a massive surprise for me. I'm not a 'magical girl' anime person but I couldn't ignore the hype so gave it a watch. Great anime in my opinion.

Really?
Naruto over Evangelion and Ghost in the Shell?

No Darker than Black?

Spirited away should be higher on the list.

Too many well known ones imho and a good few of which I don't think belong there. As others said though, it's down to personal preference. Would love to see a few different anime lists.. like how about 20 recommendations for completely different animes? Or top 20 thought provoking animes or top 20 moving animes. Or even top 20 mature animes. Too many times these lists just derail with too many Shounen which while great, are very casual watching and lack the substance many great animes have that never get a mention.

Wow. I disagree with almost all of those. ESPECIALLY the shows that are so inferior to the manga they're based on--like One Piece, RuroKen--or just plain awful, like Bleach.

I mean, goddamn, it's clear that whoever wrote this isn't really familiar with anime at all, and just tossed some titles he or she had heard of as "classics" to the list along side the few titles he or she had seen.

Gurren lagann, clannad, death note, and GTO have been some of my favorites.

I can do without all the Shonen Jump ones.

And...no Trigun? Hellsing? ugh. kill this list now.

No love for Clannad/After Story? There's a reason why it's ranked in the Top 5 anime ever on both AnimeNewsNetwork and on MyAnimeList. Only other series you can say that about are Steins;Gate and Fullmetal Alchemist: Brotherhood. Speaking on that, why have Fullmetal Alchemist instead of Fullmetal Alchemist: Brotherhood? I thought it was universally accepted that Brotherhood was the superior of the two.

Outlaw Star

Im no expert on anime, Heck ive only gone through a few series, but Bleach doesnt seem like it should be on this list. Its not particularly good. In my opinion,

Steins Gate

My Favorite is Shiki. I loved every moment of it.

Where the hell is Baccano!?!?!?

*Cowboy Bebop
*GiTS [manga > movie]
*Akira
*FMA
*FMP
*Samurai X
*School Rumble XD

One Piece, FMA BH and Fairy Tail. N

"essential"? nah

It's just a list of "anime everybody knows", but essentials? I've seen better.

It's hardly an essentials list.
If I made a top 20 list i wouldn't have too many shounen jump anime in the list.
I love them but they are plagued with fillers and some of them are just too similar.

Steins;Gate is one of the newer animes I have seen recently and loved it.

Berserk and hajime no ippo... only seen bits of the anime but if it is anything like the manga then these two should be amazing.

any episodes or movies of Lupin III should be on the list.

forgot to mention Love Hina and kimegure orange road. Two classics that deserves to be mentioned.

Needs Claymore.