What is a good Wagner opera to start with?

By far the easiest Wagner opera to start your immersion into his works is "The Flying Dutchman" ( Der Fliegende Holländer). It is a traditional opera with an overture, choruses, arias and duets but it could not be mistaken for any other composer than Wagner. Its melodies are quite tuneful and will stay with you long after the work is over. He uses leitmotifs throughout the work just as he does in the Ring cycle. I was introduced to this work on records when I was in middle school and would play it over and over again. I'd had an opportunity to see it live and was blown away by the force of the orchestra and the singers. Give it a try.

Lohengrin and Tannhauser move very slowly story-wise and music-wise. I've never been able to get through either opera in recorded form or DVD. Die Meistersinger has some glorious music, but you have to wait quite awhile to hear it unless you purchase a recording of highlights which is the way to go with Lohengrin, Tannhuaser and Meistersinger.

Not an easy question to answer. For a start, remember that you don't have to swallow the Ring in one go. It is split into four operas (strictly three operas and a 'Vorabend' - a sort of prelude). Why not listen to one of the fou, and see how that goes? I would suggest that Die Walkuere stands up well by itself. If you like it, add Rheingold, Siegfried and Goetterdaemmerung, in that order - although of course you will have started in the middle.

Alternatively, how about Die Meistersinger, which is Wagner's only comedy - although also a very romantic piece? To start at the other end of the scale, I wouldn't recommend starting with any of

Lohengrin

Der fliegende Hollaender

Parsifal

Tannhaeuser

Note that throughout this answer, I have used for example 'ae' instead of a Umlaut, for simplicty.

Starting with Wagner may not, in any case, be the best policy. When I am asked for advice about where to start in listening to opera, I recommend Puccini, and specifically one of:

Tosca

La Boheme

Madama Butterfly

(all of which, as it happens, I have sung in). Why not try one or two of those as well?

I would suggest Tannhäuser. Die Meistersinger von Nürnberg is also a very good place to start, even though a complete recording plays for about 4 hours. Tannhäuser is, in my opinion, much more imaginative and sensual...which makes me wonder why wvculturallover (I'm sure he really meant to say "immersion") can't get through it, despite being only 3 hours long. Still, to each his own. De gustibus non est disputandum.

@Richard: Please forgive the intrusion; but in what way is 'ae' simpler than 'ä', or 'oe' simpler than 'ö'? Isn't one letter easier than two?

If your keyboard won't let you type an Umlaut, leave it out. If you write 'Tannhauser', 'Hollander', 'Walkure' or 'Gotterdammerung', everyone will know what you mean.

Btw: Wagner composed two comedies. The first was Das Liebesverbot, which is rarely, if ever performed.

Smart, not going for the Ring. You do know that it is four operas, so you can take them in short doses. However, that might be a bit much as a starter. Die Meistersinger is a good starter. Tannhauser is good too. Your best introduction would be a live performance, if you live near enough to a large city or a college town.

A good opera to start with is one that is being performed close enough for you to attend. Opera is a stage production and has to be seen and heard to be fully appreciated.