I'm a hard sci-fi fan. I have been ever since I dug into Asimov's works as a kid, and even to this day, I have a soft spot for science fiction that details science that works, rather than hand-waved techno babble in a universe where space works like an ocean and the writers clearly have no sense of scale.
However, Mass Effect showed me I was wrong, that I actually liked Space Opera. My problem, in retrospect, was that I associated Space Opera with crappy tales like Star Wars and, especially, Star Trek. In Mass Effect, the writers did have a decent sense of scale (you have TWO different forms of FTL travel, and the galaxy-spanning one requires vast, forerunner artifacts), the aliens aren't from a Planet of Hats (The Salarians make great soldiers AND great scientists AND great thieves), and so on. Mass Effect's adventure was pure, thought-provoking fun!
I've begun to catalogue the Space Opera I do like. That includes Farscape, Firefly, Cowboy Bebop, Doctor Who, Revelation Space, Mass Effect and Warhammer 40k. Reluctantly, I even have to admit the recent Star Trek reboot was really great. The good stuff simplifies science, yes, but it does so in a way that people enjoy. The aliens of Mass Effect look and behave essentially like people, but that's because humans find it hard to enjoy or envision talking to a sentient bush that speaks in radio waves and thinks in blossom-colors. Ships crash into ships in titanic space battles, but that's because awesome space battles are awesome. The great space opera shows you the universe as it is, or as it might be, but through a lens of bright colors and vivid imagery that appeals to our human, animal minds. It's a galaxy filled with sex and beautiful nebulae, where broad-jawed humans blast at evil, alien overlords with blaster bolts. Hard sci-fi is great, but settings like THS are hard to grasp, to run, to enjoy.
I've never really run a Space Opera game. Most of my games are either fantasy or, much more commonly, modern horror (World of Darkness). The last time I ran sci-fi was Traveller (which, in retrospect, was also Space Opera) in high school. Thus, I'm putting together a GURPS Space Opera game, similar in form and function to Dungeon Fantasy and Action, a book of templates and rules that focus GURPS' broad toolkit down to what makes Space Opera fun. Expect to hear more about this little project over time, as it occupies my thoughts quite a bit.