We didn't ask because Londo, G'Kar, Vir is too hard to ask someone who clearly loves all of them! But if pushed, I would shag G'Kar (he seems canonically quite good in bed), marry Vir (because he needs the support and would be sweet), and cliff poor Londo with tears in my eyes.

Hmmm, Spock, Picard, and Odo. I'd marry Odo because he's totally reliable and quietly romantic (also, I think he would be a great deal of fun in bed, lol, but not for a one-night stand. It would take him a while to relax, so to speak). I'd shag Picard, because YUM. And I would apologetically cliff Spock simply because I've never felt like he was available for either shagging or marrying, alas. :)