Avalanche Whirlwind Barb
Forum user Zlexpro, who has been posting a lot of builds over the last 2 years, has created a nice Avalanche Whirlwind build for the Barbarian. The skills are pretty classical, but with Avalanche incorporated into the build, in a way that compliments all the other skills. He also has a video of the build up, explaining his choices, showing his stats and displaying how the build does on Torment 1! Check out his forum post here.
Fire Tornado Barb
BERSERK over on the official forums has done a nice guide for the awesome Fire Tornado Barbarian build. In his thread he explains the skill choices, possible gearing to support the build and how the build feels out in the fields of corrupted angels.
Fire Demon Hunter
Bleu42's Demon Hunter has gone through a few changes since the expansion hit, primarily going from Lightning to Fire, but we decided to feature his updated skill set, as his DH builds are usually very workable! On his profile you can see some key examples of fire of gear that is needed for the build and obviously - stack as much Fire damage as possible.
Bears/Spirit Barrage Witch Doctor
Battle.net forum member rockon87 has posted a guide to a pretty recognizable Witch Doctor build that has been getting a good amount of positive feedback. The build is pre-expansion, but he has updated it for level 70 and is currently using it himself. The guide is very detailed so do check it out!
Black Hole Wizard
A member of the official forums by the name of Farkon has posted a Black Hole build, which other members seem to really appreciate! It's a nice template for using Black Hole where you can switch up a few skills or passives and still have it 100% working.
There is currently a void of Crusader builds, but we tracked down what one of the most recognizable Diablo faces is using - Moldran. His Crusader is built like a Hammerdin, but also tries to be mobile. Check out the gear with which he is making the build work over here.
Invis' Monk Build
One of the best Monks in the world - Invis, has been using a very mobile Lashing Tail Kick + Epiphany build, which he does great things with in cooperative play. You can even see the build currently being used live on his stream!