Family Guy's best episodes

Is it me or do they seem to come in clusters?

in Season one, the first, second and fourth episodes (Death has a Shadow, I never met the Dead Man & Mind Over Murder, respectively) are all amazing works.

and then there's the end of season 2 which has some total jems:
Fifteen Minutes of Shame
Road to Rhode Island
Let's go to the Hop
Dammit Janet!
There's Something about Paulie
He's too Sexy for his fat
E. Peterbus Unum
The Story on Page One
Wasted Talent

Season 3 is less consistent but still follows the same rule in that, the first three episodes (The Brian leaves episodes and Mr. Griffin goes to Washington) are all brilliant pieces and then towards the end theres another trio;

To Love and Die Dixie
Screwed the Pooch
and
Peter Griffin: Husband, Father... Brother?

This said, series 4 and 5 are nearly all really excellent episodes and show a family guy that although more gag based was also a lot more sure of what it wanted to; and took advantage of that brilliantly.

Honestly, I was a little disappointed by Season 6, none of the episodes or gags were really that special.