The Baltimore Opera Company has long since shaken the stodgy reputation that opera once had. With a combination of lavish productions and funny marketing that appeals to younger generations (younger being a relative term in regards to opera: they are trying to attract people in the 30-something age range), along with program notes and projected surtitles to make the productions appealing and accessible, you can't NOT have a good time at the opera these days.
If you haven't ever attended the opera, you should think of going. Spend some time on their website to see what's coming up (they only do a handful of productions each season; the 05-06 season includes both La Traviata and La Boheme, two of the best-known operas of all time, with good reason) to find something that might appeal. If you have the time, look into volunteer opportunites (ushers get to see the shows for free).
The Baltimore Opera performs at the Lyric. Parking can sometimes be a problem, especially if you go on a night when there is also a show at the Meyerhoff. But the building is easily accessible by Light Rail, so consider parking at a Light Rail station and taking it in.