My favourite level:
Flood Zone... I've always loved the level design, atmosphere (a flooded city where you have to dive underwater in apartments and get on stairs to the rooftops etc... and then holes in the rocks on the other side of the valley opening like a door... with a battlelord and two assault commanders in it... one to each side of the battlelord. Very challenging!)
The other favourites, in no particular order.
Dark Side... I'm in love with that place near the end where TONS of kamikaze UFOs come out of that cilindrial room high in the sky, and after disabling the forcefield a battelord appearing... and then at the end in the monolith... that background "music" is scary there)
Babe Land... the first part is very mediocre, but the ship/castle fight at the end is very fun and challenging, with two battlelords... it's a cliché, but executed in an original way!
L.A. Rumble... I love the path you have to follow in that level... you start at the bottom and by the end of the level you're balancing high in the sky going from skycraper room to scycraper room, next to the big TV screen, etc... with kamikaze UFOs and commanders "bothering" you... and some cool secrets in this level oo! My apoligies for absence of battlelord fight!!!
Occupied Territory... you fight two battlelords at the same time in this level... TWICE. On harder skill levels you fight three of them, even. It's the hardest level of the game, and not only because of the battlelords... this level is the reason why I didn't manage to finish Lunar Apocalypse on the hardest skill level when I was young

Now I know you can blow up bodies to prevent the resurrection of enemies I might be able to do it
Of course there are other levels that for me stand above the rest too like Tier Drops, Hotel Hell, The Abyss, Bank Roll, ...
ultra tree 85!, on Mar 12 2007, 10:22 PM, said:
My favorite Duke 3D level would be Hotel Hell. I thought that the design was really cool, and I loved the battlelord battle outside the Hotel.

Yes, and the one inside the hotel too

And it's also fun when you destroy the fire extinguishers on the second floor so you can go outside, it's a cool fight too there, and you can pick up atomic health.
Nukem, on Mar 12 2007, 09:28 PM, said:
What was your favorite level in Duke Nukem 3d? I always enjoyed Hollywood Holocaust! That map was so big and there was so much to explore in it! I could play it for hours!
Funny I think that's one of the smallest levels actually

Compare that to Dark Side or something.