I try to get the best picture possible without mods (so far) for my PVM. I have an N64 S-Video cable, Dreamcast VGA, HD Retrovision component Genesis cables, SCART for SNES, but just have composite for Famicom and am pretty happy with the setup. I would like to have an RGB option for Famicom/NES, but that can wait.
I definitely see the appeal of a Framemeister; hoping there are some similar, cheaper options down the road.