For favorites, I generally tend to stick to the ones I watched when I first got into anime, mainly the stuff on Toonami and Adult Swim when I was in high school and college:
early Dragon Ball Z (up through the Cell saga)
the various Gundam series (primarily Wing)
More recent favorites that I've watched include Death Note and Attack on Titan.
The "Golden Trio" (One Piece, Naruto and Bleach) have all gone on far too long and suffer the same flaws as DBZ's later stages in terms of power creep, overabundance of filler, and comic-book levels of "Continuity? What's that?". Problems that comics themselves, no matter where they come from, also go through. As mentioned above, I enjoyed DBZ to a point, as well as One Piece and Bleach (never liked Naruto) but eventually they all hit a point for me where I just fell out of them.
Other anime I don't care for:
Elfen Lied (holy crap is that show dark and depressing as hell! I couldn't even finish it)
Fooly Cooly (what is even going on in that show?)
Bo Bo Bo Bo Bo Bo Bo (just... No No No No No No No)
Kill la Kill (watched a couple episodes and it just annoyed me more than anything)
pretty much every other modern shounen... I just see through the standard shounen formula too easily, the genre has become too boring and predictable