The kind of mic that I am looking for does exist. It's called a unidirectional mic, the sort that live performers use (which avoids the sound blasting through the huge stage speakers) but there is a downside to using one: you have to face it directly all the time otherwise your voice will not be audible. This would be a problem if you're recording gaming videos with voice-over because the mic gets in the way if you have to face it all the time, unless you get a smaller one that is similar to the ones attached to headphones.
I am going to check out some USB ones.
Are those what they call cardioid microphones which only pick up sound from One Direction? My microphone has a cardioid pattern (Audio Technica AT2035) and I've tested to see how much quieter it is from sides/rear. I can speak in a normal voice to the side or behind the microphone and it doesn't cancel it out entirely. It's quieter, but I think it's impossible to completely cut out the background noise.
You could also use a hyper-cardioid. But it would more of shotgun mic (or some call it a boom mic) to get the pick up from more in front of the mic than anywhere around the mic, although with a shotgun mic there can be an issue with pick up from directly behind the mic as the pick up pattern has a lot of "bleed" towards the back. This can be limited with a guard at the back of the mic (or a housing like you see with boom mics, that you see a lot of outside broadcast newscasters use where the mic is in its furry gray ferret cage). However, you'll never get true noise cancellation unless headphones are used to prevent it, as is initially required; however, its also true that a shotgun mic may not be the best option either.
You can limit the noise by using a compressor/limiter/noise gate, but then that can muffle the sound quite a bit of the audio that's looking to be recorded. But you run the risk of sounding like the teacher from Charlie Brown but with less wah-wah effect.