I'm somewhere between the only pairing I'll entertain for those characters and the pairing I most like to ship. An example of the first is Aragorn/Arwen and Legolas/Gimli. On the other hand I like Paris/Kim better than Paris/Chakotay but I believe in both. Same for Garak/Bashir and O'Brien/Bashir.

I think the term OTP came from fandoms where one relationship was favoured by a strong core of fans and edged out all others. It might have been a little derogatory used by fans who did not hold the OTP.