I don't think any are ugly!! They all have things I like and don't, either a sleek looking profile or a radical "new" Look. They all reflect the time period when they were designed, 60s 80s to today.
My least favorite is the F. I think it looks has a gothic design, and old looking starship.
Interesting thought....kinda off topic BUT
When a team or person starts thinking of a new enterprise where do you think they start?? Requirements for the mission, top view, nacelles, etc?
I would start with a plain silhouette and see where that takes me.