The fastest strictly 486 is the Intel 80486-DX4-120. This chip can definitely give the P5-60 a run for it's money. However, there are more chips on the 486 platform that could all technically be called a 486, not to mention situations like overclocking, and Socket 3 boards with 66mhz FSB support. Things like the 5x86 chips from AMD and Cyrix can definitely beat out an early Pentium.
A properly overclocked Am5x86 chip (200mhz) can beat out the Pentium in basically every task, even FSB, just because of the high speed.
This is just the pure technicality of it. It I were to be asked which one I would want, given that I have no other machines already in my collection, I would pick the 486 any day, due to the ability to downclock and exchange for lower chips, so games that only run on slower machines can work without tricky throttling programs. One thine to keep in mind with 486 machines is that most of them were VLB based, or just plain ISA. If I am building a serious gaming rig, I would need a board with PCI. This is nothing much to haver about, since both the 486 line and P5 line have PCI support.
Another issue is that while the 486 has better software support for older games, the Pentium will have support for operating systems and programs that for whatever reason insist on a P5 based CPU, even if a 486 can do everything it can.
Some of this is speculation, especially near the end, but the bottom line is the Socket 3 line has so many options, that given the right chip, a 486 based machine can without any doubt in anybody's mind beat a P5-60. As for vanilla 486, counting the 80486-DX4-120 as the fastest chip (Intel version of course) then the competition gets real close. I suggest you check out The Ultimate 486 Benchmark Comparison to get an idea of where different 486 based chips lie on the performance side of things.