Interesting, because Ive found from my fanpage that many prefer the second album, Welcome to the World and aren't especially interested in State of Mind.
I like both, but if I did have to choose one, I would pick Welcome to the World. The title track and "Last Chain" were the songs that got me into them and also started my, shall I say "quest", for Adrian's solo works and also giving them a bit more light. It all started after I watched that Adrian Smith guitar lesson video on youtube, where he played those two songs. After that, I HAD to find them.
Anyway, thats why i would choose Welcome to the World over State of Mind, purely personal reasons. Theres not much in musical quality that seperates them except in terms of style, although, obviously, having Scott Gorham and Dave Murray play guest guitars generally does help sway your opinion.
ASAP is a funny one. I sometimes love it, and sometimes dont. Great written songs, but the whole 80s-thing it has doesnt help it. Good, but not Adrian's best.
The only reasons I wouldnt pick Urchin, EPoH or The Untouchables is because I haven't heard enough of them.
Urchin I do have that relatively rare recording of Oxford in 1980, which has a large number of tracks...but they are not great quality.
The Entire Population of Hackney's recording is one of the best bootlegs ive heard and they played a lot of songs, this would challenge Psycho Motel and ASAP if it wasnt the fact it only lasted 2 nights. It would be my favourite Adrian moment ever captured on recording though. (and probably Nicko's too!)
The Untouchables apparently does have a whole live-album's worth of material, as has been quoted from Adrian himself, but unfortunately, there only seems to be those three tracks, which is a shame. Adrian once hinted at maybe releasing the album one day.