The prequel trilogy to the original trilogy show evolution of design, from fanciful to more industrial and worklike. We've seen that change in architecture in the past two centuries, where engineering has become more prominent that aesthetics. The film saga underscores this, to show time passing. Plus, the Rebel Alliance was always on the run, getting used equipment and fighters, which led to the grittier, more used look.
That look was revolutionary then; spaceships prior to ANH always looked sterile, not lived in.
I grew up with the original trilogy, so I am partial to the Hoth Snowspeeders (they make a great entrance across the screen), plus the X-Wing and B-Wing fighters. The prequel trilogy, I really like the Jedi Starfighters from ROTS; and the Naboo diplomatic cruiser from AOTC, with that huge wingspan.
Those corellian ships - Han's and Dash Rendar's - how hard could they be to manuver with the cockpit planted on one side of the ship?