My tendency is once I'm past the first two or three episodes if a series isn't complete garbage I'm hooked on the characters & want to find out what happens to them, regardless of how stupid/downhill the plots go.
Example: Dexter...seasons 1-4 pretty good, the rest was meh but I couldn't stop myself from watching - had to find out what happened etc.
Also watched Lost from start to finish in one week (almost 20 hours a day) recovering from a motorcycle accident, tons of tylenol 3 washed down with beer so I only remember about 50% of it.
Heroes, supernatural, suits, breaking bad of course.
Currently just watching Walking Dead weekly that I can think of, and then I catch up on Supernatural about once a month. GF & I don't have cable, we just torrent the show the night it airs.