I guess that I feel that orcs work best in Lord of the Rings. I'm not certain why that is. I also like the scro variant in Spelljammer (cause "orcs" spelled backwards is "scro"!

). Beyond that, orcs seem like another generic monster with little to no personality.
The Dragonlance setting replaced orcs with draconians, which worked out quite well. Not only are they a cool iconic monster of the Dragonlance setting, they've also got those nifty death throes. Even in death, they can kill their enemies.
Now obviously, draconians won't work for every setting (nor should they), but the point is that orcs are not necessary for every setting.
Orcs, for some reason, come across as "cannon fodder monsters" to me. They're there to beat up the PC's and give low-level adventurers some XP.
Goblins also fall into this trap. The recent preview of the goblins found in Pathfinder has me pretty jazzed. Suddenly, here are goblins who are fleshed out, with a personality filled with whacky sinister fun. I probably will be using Pathfinder style goblins in future campaigns.
So yes, orcs are iconic, and IMO, best left to iconic settings such as Middle Earth. If they're to be used beyond that, then let's see some true creativity go into them so that way they're more than "cannon fodder."
Disclaimer: The above views do not necessarily represent the views of the Orc Rights Council nor its subsidiaries. 