Good budget mic?

The Silver and Space Grey colors are a bit cheaper too.

As far as PC mics go Blue and Samson make the best ones. Audio Technica and others make good USB mics but Blue and Samson are very popular for PC.

A cardioid pattern is best to only pick up noise from the front for computer use. The Snowball ICE from blue has this. Samson has the C01U which is hypercardioid and a bit better. Hypercardioid will pick up lass from the sides and a bit more from the back. Regular cardioid is less from the back but will pick up more from the sides. The hyper tends to be better for PC chatting. More expensive microphones from these companies have different patterns which are of no concern for regular desktop chatting so they arn't required.

Either way both mics are $50.

Also a shockmount will suspend the microphone so it doesn't pickup desk noises or thumps as easily. $25 for the Samson and $50 for the Blue Ringer to fit the snowball ice.

Now you want a boom/arm. This will get the microphone up in the air so you can position it right in the 6" range from your mouth which is the ideal recording distance. This should pick up the keyboard noise a lot less as it places the keyboard below and behind the mic.

Cheap desk clamp arms start around $15 on Newegg. You could also hit a music store and look to see what they have for microphone arms. They may also have USB microphones at a good price.

Overall you're in business for under $150.

Now with the microphone in front of you at the 6" range and being cardioid or hypercardioid it should pick up much less keyboard noise. Also your voice will be louder with the mic in front of you compared ot the keyboard so you can set the sensitivity in windows to only pick up your voice. There is also noise cancelling software available to eliminate keyboard noise. Samson has one you can purchase.

Your last hope is to get a set of Orings for your mechanical keys to make them quieter. There is a company that sells kits for many keyboards and different switches.

A combination of all this will give you the best possible mic solution without breaking the bank and going pro. You can also get a pop filter. That's the piece of foam that goes in front of the mic so it doesn't pic up your mouth spitting or going puh puh puh.

Blue is very high quality, but many people say they prefer Samson. I can't recommend one over the other. I think either would work and purchase based on availability and price. Places like bestbuy carry the mics and a music or guitar store would carry the mic arms. My preference would be to get an arm that screws to the wall to make it sturdy and get it off the desk. Most mic arms come with a desk clamp and you can buy a wall mount for $20 and just pop the arm into that. Whatever you want.

Go with the yeti!