Well, it's been over two weeks since I began watching Babylon 5, and I managed to get through all five seasons of the entire series.

I'm not going to write an essay on every tiny little thing I liked/disliked about the series -- I don't think I have the words to convey all my feelings properly -- but I am going to list the more important ones.

Some spoilers are coming. I've bracketed them off with big !!!SPOILER!!! tags.

I liked Michael O'Hare's portrayal of Jeffrey Sinclair, thought the character had a lot of potential, and was disappointed that he had to leave the show due to his schizophrenia. Though I came to like Bruce Boxleitner and his performance as John Sheridan just as much (if not more), a part of me still wishes O'Hare could have remained on the show.
I wasn't too taken with Boxleitner when he replaced O'Hare at first; I basically saw his character as a placeholder for Sinclair with no real identity of his own. That began to change with the episode "In the Shadow of Z'ha'dum". From there on out I began to appreciate the actor and character more-and-more; once into Season 3, I officially liked them both.
As my avatar would suggest, I have become a fan of Mira Furlan and her character Delenn is my favourite character on the show. The only aspect I dislike about her was the makeup they used on her after Delenn !!!SPOILER!!!became a human-Minbari hybrid!!!SPOILER!!!. Prior to that event, the makeup artists used bold shades of lipstick that really brought out Furlan's lips; afterward, however, they used more muted shades that didn't really do her justice. I also wasn't taken with the way her hair was ultimately styled; at first they used an interesting "side-braid" style, but by Season 4 they just went with a single, flat, free-flowing style that further de-emphasized Furlan's beauty.
I ended up loving the !!!SPOILER!!!romance between Sheridan and Delenn!!!SPOILER!!! in spite of my initial misgivings with Sheridan's character and the fact that I had looked forward to Delenn exploring a romantic relationship with Sinclair before learning of how the latter character's arc was resolved after Season 1.
I have absolutely nothing bad to say about how religion was handled on this show. There was no smug TNG-styled secular humanism portraying faith as stupid and archaic here; none of the belief systems featured on the show were presented as unambiguously true and right, but they were treated with respect and dignity.
G'Kar and Londo are both awesome characters and they never fail to bring a spark to otherwise dismal episodes.
Walter Koenig as Alfred Bester was awesome. As much as I like him as Chekov on Star Trek, I think this role was far better.
I was never taken with Talia Winters and was glad when she was replaced with Lyta Alexander. Winters came off as too much of an ice queen, while Lyta was the (not so) wholesome girl next door. Of course, I am biased in favour of redheads, so ...
The way time travel mechanics work in the B5 Universe gives me a headache. While the show for the most part heavily implies that history is set and cannot be altered, there are points in the series where both the characters and the audience are shown possible futures that end up never coming to pass. I really think JMS should have made it clear whether the timeline is mutable/immutable instead of trying to mix the two mutually exclusive concepts.
Due to the limited budget, most of the action took place in and around the Babylon 5 station, with most forays to other worlds taking place briefly in shut-in rooms or as CG backdrops. As a result, the show felt a little too claustrophobic at times, especially in the earlier seasons.
I hated Garibaldi's hair and was immensely pleased when he finally shaved it off.
The pak'ma'ra

is my favourite B5 alien race.

I thought N'Grath

was an awesome character and was very disappointed that he was written out of the show after the first season.

I wasn't satified with how the Shadow War was resolved. There was just too much buildup with too little payoff. Fortunately, the following conclusion of the Earthforce Civil War helped to compensate.
Tracy Scoggins' performance on Lois & Clark: The New Adventures of Superman didn't leave me with a high opinion of her skills as an actress. Her performance here as Lochley, while not spectacular, managed to raise her status in my eyes.
Due to the limited budget, we never really get to see anyone fighting or dying in the Minbari Civil War. In light of this, perhaps it would have been better if the event had never been written into the show (even if it did feature one of Delenn's best scenes on the show).
Though I didn't like most of Season 5 -- the entire storyline revolving around Byron and his telepaths was boring and padded to me -- I felt it picked up after they were gone and came to a satisfying -- if incredibly heartbreaking -- conclusion.

Overall, while I found Babylon 5 uneven at times -- sometimes uncomfortably uneven -- it still proved to be satifying in the end. While I can't see myself sitting down to watch the series all the way through ever again, I'd definately like to own the entire series on DVD so that I can revisit the characters and specific favourite episodes/moments again.