I love me some NaLu, but I love Erza/Jellal for different reasons. NaLu is two clueless dolts who need to figure their stuff out, but Erza/Jellal is a much more emotional, painful thing.
I can see some of the appeal of Erza/Natsu, though. Especially that swoony rescue scene. But I think she's always viewed him like a cute, annoying little brother. Same with her and Gray.
Even if I don't believe Natsu/Erza is a real option, I can't stand Erza/Jellal in the same way I can't stand Sakura/Sasuke.