Boston Legal/WMG

Denny Crane is a Pokémon.
He has learned to say words other than his own name, but he lapses to being primal from time to time.

Crane, Pool, and Schmidt is a Branch of Wolfram and Hart.
Come on, it would explain a great deal about why everyone is able to get away with so much. Why? Because they've literally made deals with the Devil to keep their jobs and get a good win ratio, even when it reshapes American law.
 * And among those deals is one that destroyed the law firm in The Practice.

The Ending Is a Sequel Hook
Nothing's concluded in the series finale, and That's sequel bait.
 * Didn't that get lampshaded as well?

The whole show takes place in Denny's head
Denny Crane breaks the fourth wall a hell of a lot, most notably in "New Kids On The Block" where he welcomes new characters to Boston Legal with "Cue the music!" This, combined with the positive light Denny is always shown in.
 * Alternate theory: It's all in William Shatner's head.