Does your mic have an XLR connector? (All good studio/performance mics are low-impedance balanced with XLR connectors.) If it's the right "kind" of mic, it might have a broken connection inside. But if you can't repair it yourself, it's probably not worth paying to get it repaired. I assume you've tried a different mic cable?
The most popular mic of all time is the
Shure SM57/58 (~$100 USD). The 57 & 58 are essentially the same mic, except the SM58 has the ball wind/breath screen (for vocals). These are mostly live/performance mics, although the SM57 is used frequently on electric guitar in pro studios. A Shure 57/58 should last you a lifetime! You can get a better mic, but "you can't go wrong" with an SM 58. (I own one.)
In "the studio", large diaphram condenser mics are used for vocals and almost everything else. Again, you'll probably need to spend about $100 USD (or more). A popular inexpensive condenser mic is the
AT2020 (I've never used one.) If you spend more, you can get a multi-pattern mic and some extras like a pad (to reduce the output level with loud sound) and a high-pass filter, etc. And of course, if you spend more you
might get better sound. The AT2020 comes in a USB version, but I would not recommend that since it limits what you can do and you have the Focusrite.
The SM57/58 is a dynamic mic (with a voice coil like a mini-speaker). Studio condenser mics require phantom power, which your Focusrite can provide.
Condensers usually have more high-frequency sensitivity for a more "crisp-clear" sound, and dynamic mics tend to have a "softer" or "duller" sound.... But, you can always adjust that with EQ. Pros with access to a "mic locker" can choose a different mic for every situation. Amateurs c an't do that but we can compensate (to some extent) with EQ.
Has anyone out there purchased a mic they really like with audacity?
FYI - The
quality of your recording doesn't depend on the software. The software is essentially just selecting a digital source and routing the digital data from your interface to your hard drive as a file. If you wanted to do multitrack recording, or multitrack post-production mixing and things like that, you'd probably want to give more consideration to the software...