Nothing I try will get this thing to boot on a box with 8Gig of RAM. The menu comes up and lets me choose the items to boot, even tweak parameters, but even the old cheat of "mem=2G" on the 64-bit version won't make this boot. Always dies at Unpacking initramfs.

1) Check your ISO / media is not corrupt using md5sum, or install it on a USB stick
2) Did you try the alternative kernels ?
3) You can run "memtest" (from the same menu) to check you memory is not broken

First of all check the RAM slots. Check if it is fine. Also check if your motherboard is compatible to handle 8 GB RAM. Do check the frequency/bit rate your mother board is compatible with. Different frequency/bit rates won't work.