I can't decide between the Blue Yeti, the AT2020 USB, or the Rode NT-USB. The blue Yeti seems to be the best value, but I'm not sure about the sound quality. I plan on mainly using this for streaming/YouTube recording.
the yeti is on the large side so you might have more trouble with it being in the way or getting mic stands solid enough to hold it well. the other mics are a bit smaller and easier to manage. the yeti does however have multiple recording modes in case you want to do more than just streaming but if you do just streaming it is more overkill and just features you will not use.
both the yeti and nt have volume knobs and gain knobs directly...
the yeti is on the large side so you might have more trouble with it being in the way or getting mic stands solid enough to hold it well. the other mics are a bit smaller and easier to manage. the yeti does however have multiple recording modes in case you want to do more than just streaming but if you do just streaming it is more overkill and just features you will not use.
both the yeti and nt have volume knobs and gain knobs directly on the unit. this makes changing settings quick and easy without changing settings in windows or your recording software. while the 2020 does not have this, given that you want to stream generally your volume levels and distances will be the same so this is not a big issue. keep in mind that if you used the at2020 which is xlr (not at2020usb) which is cheaper you could use an audio mixer with it (you have to use either that or a phantom power adapter for the xlr version) you would have the same access to volume and gain.
i would encourage you to listen to a good selection of different youtubers (preferably ones with similar voice tones to yourself) who use the microphone to try and figure out which might sound best for you. that combined with what features you think you will need or how you intend to connect up to headphones if you want to listen to your voice as you record.
personally i've always thought the 2020 sounded better on recordings than the yeti in most cases. i did like how the rode sounded with a bass voice.