I think most games that aren't text heavy don't matter much.
Magical Chase has a much better looking graphical pallet, especially in stage one. The pumpkin shops add a nice autumn theme. But nicer visuals in a US release is indeed a rare thing. Usually they just censor or outright omit stuff, leaving gaps in the translation that make little sense. Not that Japan-exclusives aren't known for being a bit nutty at times. I also much prefered the title screen for Air Zonk over PC Dengin.
Blazing Lazers pops out far better in my mind going by title screen along, compared to GunHed, though the hidden difficulty menus might be missed for hardcore players. I think it's perfectly balanced at default.
As previously mentioned, anything that relies heavily on reading, like Neutopia or any other adventure/RPG, no matter how badly censored, you're going to miss out on a ton, if it's even playable at all, without an English translation.