...I guess we who didn't play MM1 in the golden years don't realize what we missed back then. But there is still time.
As for DMoMM, I recommend reading Tweakguides' hints on increasing performance for all sort of gaming rigs. I, for example, managed to reach stutter-free, glitch-free, übersmooth running at 1280x1024, 4xAA, 16xAnisotropic filtering, all details maxed out; average FPS (measured at the ingame console) is 38 outdoors, 75+ indoors. Without those ESSENTIAL optimizations at Tweakguides, it was absolutely impossible.
(P4 D945 at 4.2Ghz, 2 Gig DDR2, 500 Gig SATA RAID 0, 7950GT 512Mb RAM)
http://www.tweakguides.com/DMOMM_1.html