There are quite a few retro compliations on the PSP and this is one of the best, giving probably the best selection of games out of all of them.
1942, 1943 & 1943 Kei, Mercs, Ghosts 'n Goblins, Ghouls 'n Ghosts, Super Ghouls 'n Ghosts and the 3 versions of Street Fighter II are all absolute classics that anyone over the age of 20 must remember and will more than likely still enjoy today.
King Of The Dragons and Knights Of The Round are two arcade-only (I think), side scrolling beat-em-ups games that I hadn't heard of before but are great fun to play.
Commando, Eco Fighters, Exed Exes, Gun.Smoke, Higemaru, Son Son and Vulgus are perhaps more for the older gamers (I hadn't heard of any of these) and won't really appeal to anyone who didn't play them the first time they were out as they are very basic and, in my opinon, quite dull.
Overall this is a fantastic compilation that could have done with Final Fight, Three Wonders, Strider and Captain Commando from the other PSP Capcom collection, instead of breaking them into 2 collections, but is still great value for money for anyone after a decent and varied retro collection