Sadly, the prequels ruined this tradition by introuducing new ships and tech that were either totally fugly or derivative. Nowhere in the prequels is there anything as cool as the Tanative IV, the Death Star, the Millenium Falcon, the AT-ATs, the AT-STs, the speeder bikes, etc. The best we get are castrated yellow TIE Fighters.
I have to well disagree and agree. I personally can't say that I was all that visually impressed with alot of the technology used in Episodes I & II as the story tended really not to rely on the use of new spaceships every movie (although again I personally never took too much notice).
However the trend you say was ruined, I think actually was reborn with Revenge Of The Sith. I don't know if it's because it was the next chapter before the Original Trilogy but it was nice to actually see the Clones using X-Wing like fighters, and while I can't say I got all that into the Jedi Starfighters in Episode II, I thought they were excellently done in Episode III. I knew that if I was a kid I would have wanted to get my hands on the new Jedi Starfighter atleast. I also liked the "Invisible Hand" ships as well, they looked pretty sweet, so did the newly revamped Star Destroyers (pre Empire of course).
I also have to say that I did like the Transports used on the Battle Of Geonosis, I thought those were neat but I was more interest in that point seeing those things dropping off the clone troopers for ground battle.