Seth Godin captures my thoughts on this blog, Be careful of who you work for.
How many job offers with good pay have you turned down in your lifetime? How many clients? Compare that to how many times you've been rejected. That's totally out of whack.
Great marketing involves having a great product, and not every job (or every client) is worth your time or attention or love.
If you want to become the kind of person that any company would kill to have as an employee, you need to be the kind of employee that's really picky about who you align with.