The Fromel Shape is a great one. Your satisfaction with any EQ is really going to depend more on how close your amp itself gets to the desired tone, though. If it's way off, tweaking your signal with EQ pedals will only get you so far.
The Empress ParaEQ gives you precise control over frequencies in three ranges and offers active cut/boost to 15 dB. As a bonus you get a 30 dB boost across all frequencies. This pedal is really useful for many things (acoustic or electric), and it can handle what you want with ease. Expensive, but the amp you play is worth it. You will be able to brighten in a specific or general frequency range by choosing the bandwidth. I really love this pedal.
What Sameoldblues said about using EQ is true. If you don't like the basic sound of your amp with multiple guitars and the EQ knobs on the amp itself (and the tone knobs on your guitars) don't solve the issue, chances are a pedal isn't going to do it either.
EQs are good for balancing out your sound across the high / low strings of your guitar and adjusting for how sound bounces off the walls of particular rooms. You generally get better results cutting frequencies rather than boosting. If you try to drastically boost the high frequencies of your amp to make it brighter sounding, you're likely to end up with a lot of hiss on top of a sound you still don't like.
Not saying that an EQ pedal couldn't work for your situation, but try to use it tastefully and in moderation to get the best results.
I'm sorry, but respectfully disagree with those who mention the RC Booster ..
I've two of them ... the stock one and the SH model ..
There is always a touch of grit with that pedal on ... really nice grit ..
but it will not keep your sound clean ... lol
Some other good ones here ... the Sex Drive is very good for keeping the original sound in tact and on the real clean side when boosting...
Sorry, I hear grit in my Overdriver which is a baxandall eq as well, but no grit in the RC. The only valid complaint that I've heard around the RC is it being sterile, which it can be but it really brightens up the clean passages and playing.