Lambda the Ultimate

kind-of a fun book:

Masterminds of Programming: Conversations with the Creators of Major Programming Languages

I'm sure some of the other language designers around here have already tackled this problem, but I can't find anything in the archives...

I was wondering if anyone knows of a good list of programming problems that would be good for testing a language. I'm looking to not only test the correctness of my interpreter implementation, but also how usable some of the language's constructs are. The only test/sample programs I can think of off the top of my head would be things that a programming class would assign as homework, such as factorials, sort routines, that sort of thing. But I want to make sure I cover enough bases before I finalize my design.

I was thinking of going through the list of problems on sites such as rosettacode.org, but I'd also like to find problems that target specific paradigms and concepts (at the moment I'm looking at making sure closures are done correctly, in addition to continuations when I get that far). Another idea I had was to go ahead and translate the problems in SICP into my language implementation, seeing as how there's already an SICP translation project out there. Would that pretty much cover all the bases? And possibly add on problems from one of the standard algorithms text books?

Thanks.