Emulation is a decent subject to discus in regards to toasters, since even netbooks can emulate hardware such as the Game Boy Advance. Emulation can boost the quantity of your library of video games to sink time into significantly depending on your hardware specifications. I've personally had a lot of success with emulating the following consoles on my netbook:
Emulation obviously gets better the more recent and powerful your hardware is, but I had success with the following on my Thinkpad X200:
The best bet for emulation on laptops is to lean more towards the multimedia end of the spectrum, or at least make sure your laptop has the CPU and RAM to support high-end emulation. My A53SV could pull off the following with success:
For more information about emulating, including acquiring ROMs, emulator choices and accompanying reviews, troubleshooting, and customization, visit the /emugen/ wiki at http://emulation.gametechwiki.com/index.php/Main_Page