Hard...I've gone for a list that offers the best for that game - ie I have Uncharted 3 in both US CE & UK EE - it would be silly to mention the games twice in a list of 5...
5 - Dead Rising Zombrex Edition - gotta love that pen!
4 - Dead Island Steelbook - best stickerbook ever!
3 - Ico & SotC PS3 CE - the art is stunning
2 - MGS HD Ultimate Edition (zavvi) - the PS3 steelie is lush!
1 - Uncharted 3 UK Explorer Edition - so glad I managed to buy this back