A studio condenser mic will surely give you better results, but note they usualy need a mic preamp, aka 48V Phantom power thingie.
This condenser mic is really cheap and it seems to be pretty good:
nady studio condenser micCompared to AKG or Neumann, that may cost easily a few thousand dollars, where for a Neumann you surely pay most only for the name.
GfK is right about mobility - if you already got a miniDV camera - they usually have pretty good microphones built in, or offer a mic input for a dynamic mic. So you'll record in 2*16Bit at 44.1 kHz, CD quality.
There are many cheap dynamic mics (stage mics) that don't need the 48V phantom power, but can be plugged right into your computer or cameras mic-in.,eg. from Sennheiser, Shure, Siemens etc.
For a price overview:[a http://www.calibex.com/serv/calibex2/buyer/OutPDir.jsp?nxtg=27f40a1c0535-5BD64BBFCD48AE0F&search=dynamic+microphones&OVKWID=95750843511&OVADID=13100528511]
dynamic mics at calibex.com[/a]
Just make sure the tech details are good (low noise, high spectrum etc.) and it isn't made of plastic. If it's lightweigt then forget it. These are the mics with lots of noise when you move it in your hand.
For example this one is looking pretty good, for the price of a pizza or 2:
Nady SP3 for 18$