SC2Mapster

This maze is not only stylish as hell, but also very effective:

Well rounded maze featuring all towers of the Shakuras race:

A Vortex Trap (purple, slows enemies) and an Immortal Honor Guard avert death-by-air-wave on the last inches:

Example for a very advanced maze and a glimpse at one of the custom models:

Defense Platforms look awesome, but aren't very effective against this wave of Elite Zealots: http://www.blackcud.net/sc2/mapster/IcecrusherTD2-beamsvszealots_1.jpg

Crabmortals walk sideways, but don't be fooled by their ridiculous appearances. They have hardened shields which require many attacks to penetrate:

Example for a relatively simple maze in the midgame featuring lots of Soul Gems and Soul Projectors:

A Defense Platform oriented spiral maze fighting the first Boss: