Audio is among the most important aspects of a web conference. But which microphone should I use? A headset is almost always the preferred method. It is not only close to your mouth but keeps the same distance at all times!
My personal recommendation is the the Plantronics C720-M . It comes together with a nice case and has a USB plug. The price is about € 120.
If you do not want to spend that much the Plantronics Audio 478 DSP is a good alternative for around € 30.
Please, avoid headsets delivered with your smartphone. As the microphone is quite far away and you easily hides behind your collar the quality is not always as expected.
My favorite solution at the moment is a Blue Yeti with a flexible microphone arm and a shock mount. But this is the most expensive of the mentioned solutions and needs proper technical adjustment and preferably an additional audio mixer.
P.S.: If you are looking for a nice integrated solution without using a headset you can try a Jabra Speakerphone (€ 100). This device is a speaker and a microphone in one single case. It is USB powered and can be connected as well via Bluetooth.