Startreklover fixed many of the silent sound files that still existed in CDFalcon's "Nexus" client, polishing the "Nexus 2" client which has been the recommended client for a long time (longer than any other client, except for maybe Jon002's original client and the original CD). He has also posted many helpful tutorials under the YouTube name "LEGO Universe Now".
P.S. For anyone coming here to actually download the Nexus 2 client, it can be found at http://bit.ly/lu-d