Ordinary Day

I'd also go with Carmen and Aida as good 'newbie' operas (though I think I'd class Carmen as operetta instead, if that's the english term. Closer to a musical :) La Traviata is also good -- there was a very faithful movie version made back in the eighties that I loved, I think I'll have to think about buying that sometime now that I'm reminded.
I also like Wagner a lot, but it is indeed a bit on the heavy side. Might want to get a 'greatest hits' version rather than full operas.
(I have Carmina Burana (http://en.wikipedia.org/wiki/Carmina_Burana) on my own wishlist, what I've heard from that is wonderful.)