I have so many, as I made them, and each has a special meaning to me.
Now, if you say the Tavern, Please add a second favorite area.
For ME... wow that is hard to do.. I love most of them. (I don't like Level 4 much--that's why I have been redesigning it. It's a REAL Xanathar stronghold now).
For me, Tavern to start off.. just because it was the first area I made, and how it grew over time. Meeting friends in there, all gathering up to go down the water well to go adventuring... so many memories....
My 2 Favorites would be the Lake of Shadows and Skullport. (Ok, Skullport is more a store hub--remember when it used warp zones before the R.A.T.S Teleporters were added?
. I'd say... maybe the Drow testing grounds maybe... SO tough if you don't have a OP character!!!
What about you? What were your memories/favorite levels?