Anyone doing these? Have any favorites?

I've tried a few, and they don't really compare to the campaign because the... style, for lack of a better word, of the original is usually lacking. Still, here are my favorites:

http://www.portalmaps.net/maps/pl_glasschamber_v2.zip

(The use of glass surfaces causes you to frequently re-evaluate where you can and cannot shoot your portals to advance. Two fairly clever elements made me pause, while the rest are mostly about timing and getting into position to see the solution.)

http://www.portalmaps.net/maps/pmn_b...mediate_v2.bsp

(Just getting started with this one, but it looks interesting.)

http://www.portalmaps.net/maps/savedbycake.zip

(Kinda clever. Saying any more might give away the bit at the end, so try it yourself.)