If you check the web for internet website development they usually show survey results that MOST people are still using 800x600 as the majority resolution size. The 1024 size IS increasing in popularity but it isn't the most widely used, at least the last time I checked.
Thinking back to the good old days where 320x256 or 320x200 was a default resolution, it's interesting to even think of working at 640x480 yet alone anything higher. Bear in mind the extra bandwidth you'll need, graphics-wise, to do everything that hi-res at a good speed.
I would probably offer 640x480, 800x600 and 1024x768, unless it were a type of game that people could feasibly play at a higher res - you could always just give the option. 640x480 for some people is already pushing it.
Thinking back to the good old days where 320x256 or 320x200 was a default resolution, it's interesting to even think of working at 640x480 yet alone anything higher. Bear in mind the extra bandwidth you'll need, graphics-wise, to do everything that hi-res at a good speed.
I would probably offer 640x480, 800x600 and 1024x768, unless it were a type of game that people could feasibly play at a higher res - you could always just give the option. 640x480 for some people is already pushing it.