Problem would be games with source, and games that will run within the costraints of 68k+AGA.
Yeah, that's part of why (besides the creative aspect) I like the idea of rewriting something rather than porting it. 68k + aga is more capable than the vast majority of open source ports will allow due to the inefficiency of apis used, double-y so on amiga systems who's versions of such apis are far from optiomal (nor is GCC itself the best choice for 68k amiga for the same reason). Not to mention that aga itself has no versions of many of the dependencies most open source software requires.
Still though, I'll definately check out the links you've provided. Even if I decide not to recompile existing sourcecode, but rather write my own (port vs. convert for conversations sake) the open source world could still be a good resource for something I can do fairly quickly as the graphics, sound, maps, enemy AI (if relevant), maps, and so on are still available to me, which will help speed development up considerably.
edit: I just checked out that FreeDink "game". Not really what Im after in a "break the shackles" type project, but I'll definately add it to the to-do list for AROS

(and 68k amiga if there's enough people interested I guess(will require rtg+emulator type cpu speeds though unfortunately)).