Everybody knows what an EQ pedal does, but we’ll tell you anyway. It is a tone control that can limit or boost certain frequencies from the original tone. In this way it is a cousin to the Wah pedal, but can cover all frequencies at the same time and can be used to shape your tone. EQ pedals can also be used to cut off certain frequencies to avoid feedback and to boost your signal to overdrive your amp.
Here are some EQ Pedals for your consideration:
The Boss GE-7 Graphic EQ pedal is the best seller of the bunch. Simple to use with 8 bands of EQ optimized for guitar tones all in a rugged compact pedal. What more do you need?
The ParaEQ from Empress Effects offers truly transparent EQ (along with true bypass circuitry) and is great for sweeting your sound, adjusting your tone to the room or even controlling feedback on acoustic guitars. It offers a 30db clean boost as well.
The Ibanez BB9 Bottom Booster pedal is a marvel of simplicity with True Bypass circuitry. Give your sound a fat bottom with balls, use it for a tube screamer tone, or add it to a distortion pedal for some really interesting colors.
The MXR M108 10 Band Graphic EQ has everything you want in an EQ pedal. Extreme control over the most important frequency ranges and a huge amount of control over levels. This is the EQ that does it all.