My favourite TV show of all times is Babylon 5. Although there have been other great shows, this one rises above everyone else. First of all, the show is an epic. A space opera. Before this, most shows I had seen had episodes that didn't require you to have seen previous episodes, and wrapped everything up by the end of the show (think Star Trek). Until B5, this had (probably) not been done in scifi. The B5 story arc starts at the very first episode, and without any interruption, runs up until the very last episode. The last time I watched it, I found something in every episode that moved the plot along - even though some of the earlier episodes appear as "one-offs", they are absolutely not - they're just slowly setting the stage. You might think that this alone should make it great, but wait - there's more! The show is viewed as having launched a new era of television special effects, and you can see the CGI evolving for each season. When the show aired, this was groundbreaking. The special effects were absolutely amazing. To bind it all together, the show was incredibly well written, with deep backstories on all the main characters, surprising plot twists and gripping events. The show looks awfully dated now, but is well worth watching. For more information, see Wikipedia