I just got Fallout - The Ultimate Collection in the mail today, so I figured I'd tell you guys what you're getting - just for confirmation.
I'm also from Sweden (Europe) so I don't know if there's any oddities or errors if you compare it to the US release of this box.
The name difference doesn't make the boxes Radioactive and Collection differ, really. It's just some name mix-up, or just different name in US and UK (or something).
The CDs doesn't come in some special packaging. It's just the CDs, inside those annoying plastic envelopes you might remember from FoT.
Fallout Radioactive: This is the bonus CD someone mentioned earlier. The name of it really is 'Radioactive', and it contains various "goodies". Most notably is probably the patches. Latest updates for all three games (Fo1 v.1.1, Fo2 v.1.2e, and FoT v.1.27), and also all the manuals. You get both English, German, and French versions of it all. It also includes the Bonus Mission for FoT.
Besides those crucial goodies, you also get the installation program for Acrobat Reader - so you can read the manuals - and heaps of artwork including animated GIF's, sketches, storyboards for the intro, early screens, concept artwork, and some semi-amusing ads. The bad thing is that it's almost entirely from FoT. I think there are two items in total that are from the other games, and they're both from Fo1. One is a collage of character models, while the other is a funny hand-doodle of Mr. Handyman. The rest is entirely FoT related. Now, I know FoT was sort of impressive visually (at least I thought so) and all, but I would definitely be more interested in seeing stuff like this from Fo1 and Fo2.
So that's what you get from the bonus CD. Nothing but rather uninteresting stuff from FoT. The patches and manuals are good though, I guess. Even though they're downloadable for free practically everywhere.
About the games then. Well, I don't think there's any difference whatsoever. Fo1 even still has the problems of installing on WinXP. Oh, and the Fo2 disc isn't that gold one anymore, like the UK version of the original release was.
So, that's about it. You don't really gain anything by purchasing this box, but I guess you could look at it as an ease-of-use collection. You get all the games, including the neccessary patches in one box. Slightly more expensive than to buy them all seperately, but it might prove a bit tricky locating them all.
There you go.
EDIT: I just noticed something about the game versions. The European version of Fallout 1 always installs in version 1.2. Apparently, it has always done that. So this box of goodies becomes interesting when they add the patch 1.1. I mean, what's up with that?
Aw, man. I've always installed the 1.1 patch because I've thought it installed 1.0 with the game. Does anyone know what this 1.2 patch fixes? I haven't found any documents anywhere. Oh, I've read it removed children though, but I've never ever seen a kid in the game. Didn't know they existed even.