The first few episodes of season one are really good - well written, fairly likeable and sympathetic characters, believable plot lines.
Then the Addison character appears, and within a few episodes, it becomes obvious why Private Practice (a spinoff from this show) is so unwatchable. She is beyond unlovable to begin with, and the other cast members steadily progress down the same infernal Yellow Brick Road from the moment she arrives.
The writing is horribly overrated. The plots go from relatable to non-credible, the characters steadily lose likeability, and the show becomes an overbaked mess that tries harder and harder to yank heartstrings that its own overblown shortcomings have turned into deeply buried cables. Who would have thought that one character could wreck two shows?