I don't have orcs in my current campaign, but in my previous they were I think a cross between Warcraft and LOTR. Smart, but cruel. They had become dependant on war to sustain their economy.
I prefer the 3E style myself - a hint of pig/boar and humanoid, all in one. Past that, my second-favorite was style from the D&D cartoon - those guys looked fearsome without being too comical looking.
I like the Warcraft orcs in terms of culture, but the Warcraft orcs look an awfully lot like Warhammer orcs. For physical appearance, I prefer something a bit more humanoid rather than bestial. A slightly ennobled Lord of the Rings orc in appearance, and more neutral (rather than evil) shamanistic "noble savage" culture.