Can someone please help me understand the differences between

[U] [!] is the only one you want

>>3794805
Thanks. Could you maybe explain what most of these other ones are (aside for the obvious ones)?

>>3794805
That's wrong.[J] is the one for true connoisseurs.

>>3794871
DON'T FUCK WITH ME

The ones with a [!] in it are the verified and working dumps.
[U] is USA, [E] Europe... You get the idea.
If you ever stumble around a ROM with a [c] (lowercase 'c'), it only means it has a invalid Checksum but usually is also fine to play.

Avoid [bX] and [hXc] like plague, where X is a whole number.

>>3794897
What this guy said. Also, V is for version, obviously.

>>3794796
They're goodtools symbols, just Google it up and you can find plenty of guides.

>>3794897
Also T plus whatever language code follows it means "translated into this language".

It's usually preferable to patch your own roms to ensure that they work correctly, but if you're in a pinch this is a quick way to find a game in english. Just make sure you have the latest version.