How can I use my laptop for console games instead of my old TV?

I have a really good gaming-quality laptop with a HD monitor and great speakers, and I have a PS3, PS2, and Wii. I also have a tiny old CRT tv with mono speakers I've been playing these consoles on. No more! I want to use my awesome monitor to view my games in HD! How do I do this? I don't want to have to just buy a new tv because I never use it for anything else anyway.