This Toonami buisiness brings me to want to share a few more of my favorites.
YuYu Hakusho ~ This is a very good sized anime, and perfect for someone who wants to catch up on an awesome classic from a few years ago. This shonen series was truly my first real exposure to anime in general, outside of the occasional Pokemon episode and DBZ episode my friend forced me to watch at his house. It has a compelling plot, and characters that were unique. I must say that I also enjoyed the English Dub of the show, and I actually prefer it to the Sub, which is strange because I mainly view subs, being a sort of "anime purist" if you will. However the dub is just one of the many strong features that YuYu offers. The growth of a teen, trying to fit into the newly discovered world around him, engaging in spectacular fights between monstrously powerful foes really impacted me when I was younger, to the point that even 10 years later, I would still remember one of the lines and surroundings from an arc in the series, even after only watching a few episodes. After watching it through for the first time last year, I realize how much I missed out on when CN/Toonami stopped airing YuYu Hakusho.
Indeed, however, the engaging plot and awesome fights were not the only things this series brought to me. With this series in particular, one crucial truth was imprinted. Its good to have an ending.
Let me elaborate. Throughout the series, there were a few points where the animation or something would go sub-par to the awesomeness that had become the norm, to explain, my roommate would say that "They were working on the ending" When I got to the ending, I understood why. The fact that the creators came up with a satisfying ending that wrapped up the storyline, and left the viewers with a sense of accomplishment and resolution was a great way to close the series. This brings me to a main point about the anime I watch. Endings are good. (well, theres one ending I absolutely abhor, but thats a story for later) If the story has a conclusion in its heyday (or at most any time) the result is a complete experience that can be remembered fondly and allows for greater spread of the anime. A common trend in my dorms is watching anime with friends, and it's much easier to say: "Hey lets rewatch Code Geass/Death Note/FMA etc", rather than "Hey lets watch Naruto/Bleach/One Piece/Detective Conan/etc." Another great feature about endings is that with a planned ending, there is much less chance for the series to accumulate filler episodes/arcs/etc that really don't forward the plot in any real sense of the process. (yes, Naruto, I'm looking at you) Finally, endings are great for concluding things, and if you have an ending, its better than scrambling on, continuing with the director's random urges at the time trying to keep the show popular.
Without a doubt, almost all of my favorite anime all have endings. (bolding after the fact so that "wall of text" can be condensed)
Anyway, diverging from my rant about endings and the awesomeness of YuYu Hakusho.
A MUCH more recent favorite of mine, and also a vote for one of the best anime ever:
Tengen Toppa Gurren Lagann ~ Basically, this anime takes all that is awesome about the giant mecha archetype, goes over the top with it, adds in great plot and breakneck pacing, and comes out with a series of 27 episodes that blows someone out of the water. This series was recommended to me here actually, about 10 months ago, and I never got around to completing it. I was sitting at about episode 8 when the syncing screwed up on the episodes. Needless to say, I just finished it a few weeks ago, and I am completely in awe of the greatness TTGL exudes. The story of self-proclaimed "Simon the digger" was one that truly surpassed most coming-of-age stories, showing the frail and scared side of human emotions as Simon deals with events that shatter the bubble of his life. In the end (Yes, another anime that ends, and it is an epic ending) the path Simon takes concludes brilliantly, leaving me absolutely stunned. If you watch only a few anime in your life, this is a must see.
I've drastically shortened my TTGL section, so that people who've not viewed it yet can see it without spoilers...