if you can just spend alittle more money you should be able to find a 64mb or even a 128 mb ti4200 for around 60-90$ that would be a much better pic the a mx or a 9200 by far . but if you can't spend the extra . either the mx or the 9200 will work fine . like butch says . if you don't need a really high res or all the eye candy on either will work fine . my son ran halo on a 32mb gf2 for the longest till he got a 9600xt about 3 weeks ago .
check the newegg refurb section monday or tuesday . you can get ti4200's there alot of times for about 60-75$ . that is alot better money spent than a gf4 mx or the ati9200 in any version .