thumping in front tire

What is your question?

I just took my Bravada to a local mechanic to fix a thumping on my Bravada's drivers side front ture. They found that the alignment was off and realigned the vehicle while replacing all 4 tires. (The wear was pretty uneven all the way around.) Unfortunately, the thump is still there. What could be wrong? (PS I have 150K miles on it & plan to keep it another 2 years...)