Taking goofy to mean funny, lame as hell, or just generally goofy, here's what sprang to mind as I browsed the episode list:
Conspiracy, The Outrageous Okona, The Royale, Samaritan Snare, Up the Long Ladder, Manhunt, Deja Q, Captain's Holiday, Hollow Pursuits, Family, Remember Me, Devil's Due, The Nth Degree, Qpid, In Theory, Disaster, The Game, A Matter of Time, Hero Worship, Cost of Living, Time's Arrow I and II, Relics, True Q, Rascals, A Fistful of Datas, The Chase, Liaisons, Sub Rosa, Genesis.
Most of these aren't very good
If I had to pick a top 5 for being both goofy and actually good:
The Royale
Deja Q
The Game (this is mostly good because of how terrible Wesley is)
Rascals (I actually like this)
A Fistful of Datas
There's not much I really find goofy on TNG. Lwaxana episodes almost always feel a little goofy, but they're so bad. Q episodes are good and goofy most of the time. Anything involving kids other than The Inner Light is normally goofy. The Holodeck episodes. Up the Long Ladder is kinda so bad it's almost comical it got put on the air, but I have a soft spot for it.