If I recall correctly, the statistics are that 25% of people almost always get motion sick, and 25% of people almost never get motion sick.
The three best methods to alleviate motion sickness are
>to blur and darken the edges of the screens (picture a flashlight, for example)
>to have a consistent line of horizon that stays in one spot (racing games that go up and down hill are the worst offenders, I've heard)
>to make any movement acceleration smooth and gradual, from 0 to 10, 30, 50, 70, 100 instead of 0 to 100. I've heard Minecraft gives motion sickness due to movement speed being consistent.
All around, you want a game with no line of horizon that moves up and down a whole bunch, with bright environments and no flashlight effects, and movement that goes from full stop to max speed instantly. Good luck.