When I found Otherspace, I wasn't looking for a MU*. In fact, I had never played one before. I was a long-time veteran of tabletop RP, and had owned my share of dungeon crawler computer games, but had never really played an online game. Now that I've been on OS for six or seven months, I can honestly say that I couldn't have picked a better place to start.
Otherspace is a true Role-playing enviornment. While this means a bit of work to learn the totally original theme, it is well worth the effort. In a very short time your character becomes totally immersed in his or her own relationships, employment, adventures, travel and soforth. Most of the intial learning curve is covered in the application process, where you craft your character to your original concept. While not all applications are approved on the first go-round (a real admin reads each one and approves or rejects it), we now have a Realm of Dream where those awaiting approval, characters who are not in IC mode, and those who have passed on can interact in freeform RP.
Otherspace also offers plenty of room for exploration, with an entire galaxy (and in the future, different galaxies) to explore and a number of playable races, from several 'flavors' of human and humanoid, to catlike Demarians, lizards, insects, and a sentient robotic race.
The admin on OS are friendly and helpful (and I don't say that only because I now am one;) and always willing to help out new players, both with establishing their character concept and with any troubles after creation. Don't be suprised, though, if they tell you to "Look it up" if your answer is in one of the comprehensive and easy to understand system of help files. After a few days, you'll get the hang of it and find your own answers in no time flat.
Otherspace is an exciting, fun, and immersive RP enviornment, and I would encourage anyone interested in RP, especially of the sci-fi variety, to give it a try.