off the top of my head:
DRAMA
twin peaks (first season is all-time number 1 pick)
the wire
deadwood
elfen lied
death note
claymore
breaking bad
justified
buffy
veronica mars
COMEDY
the simpsons
arrested development
south park
fawlty towers
father ted
peep show
limmy's show
space ghost c2c
jam
the thick of it
extras
it's always sunny
downtown
FLCL
xavier: renegade angel
i have tons of acclaimed TV still to see, but i can highly recommend all of the above. also, house and prison break are huge guilty pleasures. 24 is a huge mostly unguilty pleasure, it's mostly so good. also love old cartoons like ren and stimpy, taz/animaniacs/pinky, wacky races, x-men, courage the cowardly dog, rocko's modern life etcetcetcetc.
shoutout to 3am favourites takeshi's castle, banzai and robot wars. and i watch pointless nearly every day.