The Lord of the Rings Online's Book 11 introduced Gollum as a character with whom players could interact. His cameo appearance was a fun addition, albeit a minor one. Turbine hasn't forgotten him, though; he's the subject of the Lorebook entry most recently featured at the official LotRO website.
The entry tells the "sad and perilous" tale of an innocent little fellow who was consumed by his "precious" -- the One Ring which at first seemed pretty and innocent, but which drove him to murder. We all know the ring is neither pretty nor innocent. As Gandalf said: "it wants to be found," and the one who's looking for it is none too pleasant.
Gollum is one of the classic characters in English language literature. And if you're a fan of the movies as well as the books, then you'll surely agree that Gollum is the greatest CGI character in film history. Don't even get us started with that Jar Jar guy.