Actually, I would think that the majority of MBC1 (at least those released outside of Japan) and all MBC2 games would work fine with an MBC3 or MBC5.
First, all the MCB1 games released outside of Japan contain no more than 512Kbyte ROM and 8Kbyte of RAM (with the exception of Mortal Kombat 1 & 2, which uses 1Mbyte of ROM and 0Kbyte of RAM). MBC3 should be able to support any MCB1 game with a ROM size less than or equal to 512Kbyte. Both MCB 1 & 3 support banking for up to 32Kbyte of RAM in the same way as well as RAM enabling. MCB1 uses five bits (512Kbyte or less) for selecting a ROM bank, MBC3 uses seven and they are in the same place. MBC5 supports 128Kbyte of RAM, but the selecting bits are in the same place. MBC5 uses 9 bits to select a ROM page, but the lower bits are also in the same place. Mortal Kombat 1 & 2 would not work in MBC3 or 5 because the manner in which it selects banks above 512Kbyte is not supported on those devices. Games with 512Kbyte ROM/32Kbyte RAM should also work, the write to
MBC2 games are very similar ROM-select wise to MBC1 except that they use 4 bits in the same area as MBC1, 3, 5. The 512bytes of RAM are in the same area as the 8+Kbytes of MBC1, 3, 5. One would hope that since the RAM is supposed to be 4-bit, yet the bytes read in an MBC1, 3, 5 would be 8-bit, the game ignores the upper nybble. The RAM Enable value (0A) should be the same as in MBC1, 3, 5. The only peculiarity is that MBC2 will only write to certain areas to switch ROM/RAM banks. Such writes would still be valid on MBC 1, 3 or 5.
Of course, if the old games do things like write in the 3000-4FFF area for ROM select on an MBC5 or use a write value with 1s above the 4th/5th bit, they may select the wrong ROM bank. Similarly, using a write value with 1s above the 2nd bit may select the wrong RAM bank.on an MBC5. This also applies to an MBC3 game. ROM only games should also run just fine, as they have no reason to write anything to the bankswitch controller.
I used the following sites in figuring this out:
http://nocash.emubase.de/pandocs.htm#thecartridgeheader
http://verhoeven272.nl/cgi-bin/FSgz?fru ... &GBcontent
So, if you had an MBC5 cart, you could play all games except those that use MBC3 + RTC, MMM01, TAMA5, HuC-1, HuC-3, MBC4, MBC6, MBC7, Camera,