Disclaimer: I'm no expert on PL research, and haven't read any of the texts you mentioned (bought myself Purely Functional Data Structures for Christmas, but it's sitting behind several other books on my to-read list). That said, the titles you mentioned reminded me of Steve Yegge's list of advanced reading for programmers:
TaPL and PFDS are both on the list. Given what you wrote, I thought perhaps you'd be interested in some of the other entries, such as "Programming Language Pragmatics" or "The Essentials of Programming Languages".
http://sites.google.com/site/steveyegge2/ten-challenges
TaPL and PFDS are both on the list. Given what you wrote, I thought perhaps you'd be interested in some of the other entries, such as "Programming Language Pragmatics" or "The Essentials of Programming Languages".