So, I got curious about how well my recollection of Tolkien's orcs has held up over time and found http://scifi.stackexchange.com/questions/11859/were-there-ever-any-good-orcsarticle about whether there was ever a "good" orc depicted in Tolkien's works. This article seems like a pretty balanced discussion and it turns out my recollection was pretty accurate.
The only example of a "good" orc anyone came up with was Ugluk, who was goal oriented, strong, not at all cowardly and put up a good fight against Eomer. Of course Tolkien's book also says that Ugluk preferred 'man flesh' to horse meat, loves to fight and kill men, drives his soldiers harshly, would rather kill the Hobbits than lose them and that he blindly follows orders. And this was the best example of a "good" orc anyone in the discussion could come up with.
Someone also quoted "Orcs will often pursue foes for many leagues into the plain, if they have a fallen captain to avenge (FotR 351)" for the argument that orcs can be loyal, although I think it is debatable that this type of revenge motive stems from actual loyalty. Seems more likely it is more an animistic instinctual reaction to a threat against one of their group, which by extension is a threat to all of them. And the same person who argued that orcs pursuit of revenge for a fallen captain demonstrated "loyalty" also admitted that "It is also known that orcs secretly hate their masters and miserable life they were forced upon."
So, there you have it, no "good" orcs in Tolkien and only one who was slightly less despicable than the rest.