Okay I admit.

I think it should be Locke/Celes and Terra/Edgar, But strangely enough.
If Rachel was alive I'd go for Locke/Rachel, only because Celes seems like she'd be clingy and Rachel seemed to be more innocent and Locke was the adventurer, Celes seems like she'd go on adventure's with Locke but then someone grabs her and she'd be all "OMG-LOCKE-I-NEED-SAVING-BECAUSE-I-JUST-LOST-MY-ADVETURER-SKILLZ!!!!!!1!1ONE!!1!" so it'd almost seem clashing, Rachel just shouldn't have gone on the adventure's and just awaited Locke to come back. Celes' couldn't handle that.

I think Terra and Edgar are just cute 'cause they're awkward, and there's nothing wrong with awkward relationships that tend to not go very far because the awkward-ness. o o;;;
If that makes any sense.