I am fairly new to Linux so I tried the first thing available which was Fedora Core. Installation went smooth except the screen resolution was really low. I just got a small box screen on my 32" HDTV and I couldn't find a way to configure it to show full screen. The GUI settings wouldn't allow me to do it. I tried searching for a way to change some config file(s), but no luck. Maybe more experienced users would know how to do this....
So I moved on to Yellow Dog. It was tailored specifically for the PS3 and it shows because I didn't have the above problem. I also liked the interface more as well.
I heard Gentoo was the best.....if you're an experienced user. But for me, I'll stick to YDL til I learn more about the OS.
I feel YDL is the best initial setup, as Terrasoft has the most tailored distro for the PS3, they have access to some of Sony's technical resources to continue to upgrade the OS. For instance, they have a wireless driver in beta test right now, due in part to Sony releasing technical info on that. Once that is released, I am sure other distros will compile their own versions.