Two nice ones are Gurren Lagann and Full Metal Panic, Gurren Lagann only has 17 episodes I think but Full Metal Panic has three seasons/series, I said series because The second one: Fumoffu has a more comedic feel and the third: ironically titled second raid is more serious. The first is more of a micture between the two
You're missing some episodes of Gurren Lagann. It's a full 26/27 episode anime. Full Metal Panic has 3 seasons: Full Metal Panic!, Full Metal Panic? FUMOFFU (can be skipped or jumped right in and is purely there for comedy gold), and Full Metal Panic: The Second Raid, the real continuation of the first season.
All that I can think of have been mentioned, but I'd like to further reinforce recommendations for:
-Trigun (26 episodes)
-Baccano! (13 episodes and 3 episode OVA series that are basically episodes 14-16)
-Ghost in the Shell (movie, then Stand Alone Complex)
-You already started TTGL
-Fate/(Stay Night and/or Zero) (Former is about 26/27 episodes)
-Wolf's Rain (30 episodes, but that includes 4 back-to-back recap episodes that you can skip)
-Rurouni Kenshin (if you can sit through a bit over 90 episodes, plus 2 OVAs).
Don't remember if these were suggested (probably were), but also:
-Cowboy Bebop (26 episodes)
-Hellsing: Ultimate Series (4 dubbed OVA episodes, the rest still need to be dubbed)
-Outlaw Star (26 episodes)
-Yu Yu Hakusho (112 episodes)
-Anything by Hayao Miyazaki