If you play a game in a window instead of fullscreen, what is your preferred window size?
Not fullscreen (since I have problems with fullscreen in linux with a dual-monitor setup), and then 800x600 pixels 
For applets/Flash games in my opinion optimal size is 800X650 or 900X650.
Thanks for the replies! I’ll go for roughly 900x650 then.
Why those numbers?
800X650 and 900X650 in my opinion are best values for 1366X768 screen - nothing is clipped, you have some space for another things at the left or right.
I hate it when programs make the window too big for my screen and disable resizing.
I always make my screens resizable and have the default resolution at 800x600 because it fits on nearly all common screens.
(As a side note, anyone ever used their TV as the monitor for their computer? If you can, it is Awesome for gaming. You just need a wireless keyboard & mouse)
I hate it when people complain about my window sizes because they have to use a screen resolution that became outdated around the time I was born. ;D
My screen is 1366x768. I tried to play a game that was 1024x800. I couldn’t find the “Main Menu” button.
Bring out your trusty old Notepad and hack the .ini configs?
I usually release with 2 Display Mode’s available:
800x600.
640x480.
More listed here if you’re still not satisfied:
I’m always using 800x600 during the development process. Higher resolutions are good but they often depend on the players available hardware.
I usually use 640x480, it will fit on pretty much any screen which is why I use it.
I use 648x480 or 800x600 initially because all modern screens support it. then i’ll let the user change it to what he wants.
OP asked when we play games…
do you guys srsly play games in 640x480 or 800x600 ?
I dont like fullscreen because of messengers and all, my screen is fullHD 1920x1080 so I usually just take one size lower like 1600x900 or a little bigger
when programming I set it to default to 720p
1024x768 or 1024x600 is the lowest resolution for our biggest game, I think its even go 800x600 because I had to draw the line somewhere and this isn’t 1990 D:
I have a big TV connected to a separate PC. mostly for watching movies and shows, but also games
did that after my laptop’s screen got giant 2 inch black columns. ut99 was great in widescreen.
After SVGA (800 x 600) the next popular size was XGA (1024 x 768). These were 4:3 aspect ratio. After that things became a fit more varied. I used SXGA (1280 x 1024) quite a bit, but it has a different aspect ratio. Then came all the widescreen resolutions in 16:9 aspect ratio. HD 720 (1280 x 720) seems a reasonable minimum for those. So unless you can change the aspect ratio of your game, it is hard to use all the screen area.
I like 800 x 600 for embedded java and flash, as it leaves plenty of room for sidebars on a modern monitor, which is probably at least 1280 x 720. It would also be useable on 1024 x 768 with a bit of window scrolling, provided the user doesn’t have a zillion toolbars enabled in the browser.
For a pop-up window, you need to leave room for the borders. If we assume a minimum of 1024 x 768 and then consider that a HD screen may only have 720 vertically, then 1024 x 720 less window borders is about the top. Someone mentioned 950 x 650 which seems a reasonable maximum. I still have a soft spot for 800 x 600 as it leaves some room for OS toolbars etc.
For full screen, one really needs to go for the largest native resolution, since most displays these days are LCD and do a poor job with anything else. Thus coping with arbitrary aspect ratios needs to be considered. If it looks ok on 1024 x 768 and 1280 x 720, thats probably ok.
Either you’re a child prodigy or you’ve never heard of netbooks 
Mine has a native resolution of 1024x600.
I have to program my games @ 800x600 if I’m doing 3D lol.
Any higher my computer can’t handle it :S 640x480 for less lag on 3D.
I usually go 900*500, gives me a nice wide screen
Mike