I started working at a company out of college, and a year in, after a good performance review, got a 2% raise. I found out that this put my salary at slightly less than the company was offering new college hires for the current year.
So I confronted my boss about this, and asked for a 4% raise (including the 2% I was offered). While my boss agreed (or at least said that he did), HR blocked it, and so I was left with my 2% raise.
I did what most people would do - I found a new job and gave a generous 3 weeks notice. The counter offer was $20,000 on my next paycheck, if I promised to stay for at least another year. The raise that I had asked for was $3500 over a year. Naturally, I turned this down.