Space-based MMOs are few and far between, which is why we're putting two classics up against each other.
Despite MMORPGs being one of the most saturated genres on the market there have been relatively few set in space. The ones players currently have access to are relatively old but seem to have weathered the test of time. Two of the most popular space MMORPGs still around are EVE Online and Vendetta Online.
While these two might appear similar on the outside, there are quite a few details that makes one unique in its own right. EVE Online is a true point-and-click RPG while Vendetta Online combines sandbox RPG elements with twitch-based gameplay.