;) I always liked the episode where they said they couldn't do something because it violated "The Prime Directive" but then went ahead and did it anyway. ;)
But seriously my favorite episodes were:
Elementary, Dear Data - first Sherlock Holmes Episode
Q Who? - despite what they later may have become its the first borg Episode
The Offspring - Data builds and Android(which no-one else can seem to do)
Clues - The Crew is knocked out and data lies about the length of time
Darmok - "Darmok and Jilad . . . at Tenagra"
The First Duty - Wesley's flight team has a death
"The Next Phase" - Geordi and Ro are Cloaked - I just like the end payoff
"The Inner Light" - Mentioned previously ,its one coming out and is probably at the top of my list of favorites - probably Patrick Stewart's best
A Fistful of Datas - Computer malfunctions as Worf and Alexander are in the Holodeck where all computer characters are eplaced by data
Ship in a Bottle - the second Moriarty one
Starship Mine - Picard trapped on Enterprise during energy sweep
Lessons - Picard falls for an new officer
Timescape - A time anomaly episode
Phantasms - Data has a new dream program
The Pegasus - A search for a federation ship with a prototype device + Terry O'Quinn
All Good Things - One of the best series finales for any show ever(it left you satisfied with the ending but with hope(or at least a basis) that it could return - not that it would outside of movies - it just didn't "destroy" the basic premise of the show like so many series finales do.
Note These are just my favorites and even this is a trimmed list. I like "mystery" episodes with the occasional just well told story(Inner Light).
Them's fighten' words -P
As for Enterprise, as stated the last 2 seasons far exceeded the first 2. Plus it had Commander Shran.
The majority of the episodes in the first 2 seasons suffered from what I call the "Instant Solution Syndrome". The episodes spent 40 minutes building to a climax then were resolved it seems in 2 minutes. Then the credits rolled.