I'll add a bit more to this thread. For Final Cut Pro, the latest officially supported version is FCP 8, but FCP 9 can easily run on a PPC Mac, simply by changing a line of code or something in the installer which bypasses the system scan and allows FCP 9 to install. After that, everything works perfectly. I've got it running on my dual G5.
Also, I *think* that the latest Adobe suite that is PPC compatible is CS3, except for Photoshop, which can go up to CS4.
Most flash stuff requires version 10 (don't quote me on this) but the latest version for PPC is 9. Some helpful people recreated version 9 disguised as version 10. That also works perfectly on my machine.
Also there is a way (sort of) to 'run' Mountain Lion on PPC machines by installing a very believable theme called Mountain Leopard - should be able to find it somewhere on the forums.
Minecraft can go up to version 1.5.2 (with a small tweak), while the latest version is 1.6.2 (as of now) this is because PPC macs don't support Java 1.6, only 1.5.
I'll do a bit of research and I might add another post with more info. Hope this was useful

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For many PPC apps, you have to apply a small tweak to get it to run a newer version than what is officially stated. In this day and age - well - we kind of have to deal with it because very few 'big' programs support PPC, simply because they have no reason to do so. PPC is slow (there are a few exceptions), far too different than other processors, old, and very few people use it. Without a tweak or two, you'd be stuck in the early 2000's.