If it doesn't have 10MB of RAM already, I'd upgrade that first. Many games of the era must be run in 256 colour mode, not in thousands of colours mode, so I'd grab the FPU next rather than the VRAM (the VRAM upgrade adds the option of 65,536 colours to the stock options of B&W, 256 greys, and 256 colours). The FPU will help with a few games, but certainly not a majority. Sim City 2000 will run a lot better with the extra ram and FPU than stock, for example.