When it comes to the law, there are many, many options. The holy grail when it comes to practicing law is working for yourself. If you can secure enough clients and keep your overhead low, meaning an executive suite somewhere with an assistant and that's it, you can make huge money. Law is unique in that you can make real money with minimal overhead if you know how to do it.

So your question should be "how can I get my own clients so I can go solo?" Big law is not the answer. You might be able to generate a valuable book of business which will help you move from one big firm to another, but you probably wont be able to go solo and take them with you. So you need to leave big law for a normal law practice that allows you to generate some kind of specialty that allows you to generate clients that you could take with you.

Think about it, right now you have some kind of bonus structure, something like you bring in three times your salary and you get a % of the extra as a bonus I imagine. This is because you have to cover your own salary, the firm over head, and the partner's bonuses before you get a piece. As a sole practitioner you get to keep everything you can kill, minus a minimal about for overhead.

So go learn family law or bankruptcy or something, figure out a way to get clients, and when you have a bunch go solo.