Penetration by Ingo Swann - mind blowing stuff. Also recently read Dimensions by Jaques Vallee, chronicling the correlations between modern UFO/ET experiences and ancient mythology- some fascinating ancient accounts with some interesting insights- I suppose it all ties in together on some level. Just picked up Diary of a drug fiend by Aleister Crowly- Only a chapter in but interesting so far.
I just finished 'Penetration' and I'm almost ashamed to admit that I haven't got round to reading any Vallee yet - even though he is top of my list.
Right now I just found in a charity shop a copy of 'The UFO Experience: A Scientific Inquiry' by J. Allen Hynek. I have read 'Night Siege' which was a good account of the Hudson Valley sustained flap of a few years, it's a shame that the revelations about the co-author, Phil Imbrogno, cannot but mar the authenticity. I have argued that even accepting Imbrogno's fake military claims and educational claims, his reporting of the flap may be accurate, it's just that it's hard to be sure when someone is exposed as having perpetrated pretty huge lies over a long period of time.