Hat e to see an opening I do not know well. Has to be sound however.
Most dreaded/favorite opening to face?

I am a 1. e4 player and too old to "restart" but if I had it all to do over again--I would open 1. c4 The English Opening.
Do not like to face that opening...

I play against e4 using sveshnikov= I like to play e4 c5 nf3 nc6 d4 as black. My favorite white one is v.s a hedghog setup normally coming out of a Nimzo indian 4.Qc2 c5. I hate it when my opponent plays 1.d4

Most dreaded..hmmm...
The Catalan is fairly difficult, especially in CC. But I really dislike playing against stuff like 1.f4, its a little boring.
Favourite is the open sicilian as black.

as a 1.d4 player, i love seeing the marshall defence (1.d4 ... d5 2. c4 ... nf6) and dread the kings indian

from black perspective i love anything really, except perhaps 1. f4 and 1.b3 as I have to think more from the opening

As white, I love playing against the KID and hate playing against the Benko.
As black, I love playing against e4 and hate playing against the Stonewall.

I love how everybody hates the Caro-Kann...just warms the heart as that's what I play.
As for myself, being a 1.Nf3 player, I love facing 1...d5, and hate playing against the Modern (1...g6)

I think b6 openings. As your not sure what your opponent is planning and have to wait an extra move than usual to determine it.
I love playing the Benoni, KID, and Najdorf. I hate to play against the Caro Can and French.