Either specific ships, or races as a whole, both are fine.
The Rebel Valhalla is easily my favorite cruiser design in the game. The entire rebel style is the most identifiable to me, even if it isn’t the most original. I wish the Fenrir was scaled to match the rest of the Rebel cruisers- I think its a little small as it is.
The Alliance is the most original, IMO. They’re not my ‘favorite’ looking per se, but they’re imaginative, well-modeled, and despite being many different shapes, they all look like they fit flying next to each other.
I like the unique look of the Imperials, but honestly, I think the circular design is a little repetitive. I think at least one cruiser and one frigate could be swapped with something ‘different’- even something based off of another geometric shape, or circles re-oriented in another direction. Their largest Cruiser is my favorite of their ships, because it conveys their motif the best. Their fighters look strange flying around each other, because they’re such different sizes.
The Federation are my least favorite. They do fit next to each other, but that’s because they all look basically the same (like a pile of square blue LEGOs, arranged in round shapes). Some of the designs just look clumsy; clearly function over form (I do like the frontal arrangements of weapons). It’s nice that they look distinctly different than the Rebels, but they also do feel a little redundant in the overall game.
Edit: And what’s the deal with the Rabbit? It looks like nothing else in the game. Weird.