Which is better for MS-DOS games?
As DosFreak also suggested as long as don't boot Windows. But both 95 and 98 Pure MS-DOS versions should run DOS games just fine and on par with probably DOS 6.22. The benefit of 98 would be access to FAT32 partitions. but for the sake of compatibility I recommend making a 2GB FAT16 partition as the primary partition on the boot drive as not all DOS programs would respect FAT32 partitions and possibly may not function properly. The best way for a beginner to bypass the Windows 95/98 Gui without any modifications is from within Windows restart the computer and then it when you start seeing the BIOS screen pop up like when you first turn on your computer constantly tap the F8 key at the top of the keyboard constantly until it enters the Windows 95/98 Boot Menu and gives you options. Windows 95 / 98 DOS loads in less than second so sometimes this is the only way to get in before it going into the Windows GUI and then you'll have to repeat the process.
One of the 95/98 Boot Menu options is "6. Safe mode command prompt only" if you want to avoid loading the Config.sys or Autoexec.bat. If you have created your own customized Config.sys and Autoexec.bat then there is another option for "5. Command prompt only" which would load those two DOS boot files first Config.sys then Autoexec.bat.
Here is an idea of how the Windows 95/98 Boot Menu looks like using the F8 key.
If you get advanced you can start modifying the MSDOS.SYS file to automatically go to this menu by default and run your Windows 95/98 at the Command Prompt by typing "WIN".
But the F8 bypass trick should work on all 95/98 systems.
And just for clarification as to why run DOS programs in pure Windows DOS rather than inside the 95/98 Command Prompt. Not every DOS program likes being run inside Windows which cause compatibility problems. And if you hit the Windows key for example sometimes this will also crash the program if it manages to run in the first place. Also some DOS games want the most conventional memory as possible so even using exiting from Windows 95/98 to DOS you're also going to lose the most conventional memory you can achieve then say booting straight to Windows 95/98 avoiding the Windows Gui. So if your goal is running DOS games you are better off modifying the MSDOS.SYS and configuring it to boot straight to Windows 95/98 DOS. Between the two I prefer 98SE DOS only because of it being the last official MS-DOS revision and it supports FAT32 in case you need to copy directories/files from a FAT32 partition onto the FAT16 partition boot partition for running it in the cleanest most DOS compatible state aside from running pure MS-DOS 6.22 and lower.