If everything you play is 1024x768 then they must be all old games? all new games have a selection of the most common screen resolutions, even if they dont have your screen res in the options most games can be still be changed, like on Battlefield 2142 that i play it doesnt list 1440x900 widescreen so theres a little tip to change it to whatever you like(right clicking the game icon going to properties, then in the target box change the info to your screen size).
Anyway having a bigger resolution means it looks better basically because there are more pixels per inch on the screenm but to keep the graphics setting the same you need a decent graphics card