I've played all the Steam workshop maps and there are some very good ones -- WG series, Roch, Turok, various one offs...
Undertaker's series, culminating in Blink of an Eye, is the best series.
Honestly, this map in particular is HUGE yet balanced, clean, and challenging (I still can't beat it in one try). I love the fact that the player can choose the Project Blink path OR the Transport/City path with the Blue Card at the beginning. I love that the Duff Factory is a side quest. I love the unique challenges like the Gold Vault.
This map ALONE is about the size of an entire Original Episode.
Just amazing, thank you Undertaker!
PLEASE MAKE MORE!
PS The other levels in this series are ALL GREAT: Forever and One More Day, Day After Forever, Desert Complex, Brainwash Facility, Border Town. Try them all -- and good luck by the way!

Awesome map! Soo huge, complicated and balanced! Possible the largest map in all Duke history. It was difficult to find the way till the end. But it was soo interesting! 1000+ monsters killed:) Thanks!!!

Amazing map!!! I enjoyed it the most with my coop partner!

I'm super happy to hear that! :) There will be no more maps from this series, but I plan on starting another one - maybe in a little different theme :)

Awesome map and an equally awesome series! Hope to see more installments in the future.