Phantasy Star Universe never achieved the success of its predecessor. It removed a lot of the simplicity PSO had and added questionable mechanics, like tying your abilities to weapons, or needing to grind classes. It also had long multi-section areas rather than the more organic PSO zones. Because of that, and other reasons, both the PC and PS2 versions of the game were taken offline. Yet the 360 versions still exists, and has passed its 4th year of operation.
Even PSU with all its faults is a fun game. What I miss the most is the techno-anime style it had. The Phantasy Star Online series has such a different aesthetic, combining traditional fantasy with science fiction for a unique style. PSU had some nice little touches that other MMORPGS may want to use. One of them was simple: characters could switch between male and female style emotes by holding down a key. They also could speak in chat through an anime-style cutout, shown here.
Currently it and FFXI are the only true console MMOs surviving. Theoretically Everquest Online Adventures should be too, but last I heard Sony was turning off the old PS2 DNAS servers, preventing people from connecting to both it and FFXI via PS2. Here’s hoping that PSU continues to survive for many more years.