I LOVE LOVE LOVE ER.
I've had surges of watching it here and there since 7 or so years ago.
I'll watch for a couple of months, not watch for months, catch a few episodes, not watch for a couple of years, then watch for 3 months, etc...
hopefully someday I'll get all the episodes and watch them from the beginning.
These are awesome, awesome shows and it amazes the attention to detail that goes into this.
Highly underrated because the cast isn't as high-profile as it used to be and because it's lost viewership after the departure of Friends and Seinfeld.