This question should get a lot of responses.
It sounds like you would want any of the inexpensive Condenser mics. There are a number of them available from companies (US?) such as CAD, MXL, Behringer, etc. Ranging in price from $79 to $199. Condensers have a very flat frequency response and are perfect for recording vocals or acoustic instruments.
Generally there are a few variables to look at.
- Type of Mic: Condenser or Dynamic
- Pattern: Cardioid, Omni, etc
- What are you using to record.
- What type of room will you be recording in.
For single person vocals, a Cardioid pattern is usually best. For a group or the piano an omni directional mic may work best.
However, condenser mics are very sensitive and will usually pick up a lot of sound that a dynamic mic will not. This can help a condenser cardioid act like an omni.
Condensor mics will require Phantom Power from the device you will be plugging them into. So you may need an inexpensive PreAmp if your DAW or mixer cant supply it.
I only have personal experience with the Behringer B-1 and it sounds good enough for my uses.
