My laptop has been overheating lately and I've been looking into getting a cooling pad for it. What's a good cooling pad for approximately $20?
You say "lately", so it probably needs some cleaning. If warranty isn't a concern, you could open it and clean it a little. Maybe even put new thermal paste.
Any of them work good in my experience. I got one that used a USB for power, alternately some have batteries. just look at how the fans are laid out and make a pick that works for you, I use one where the whole surface of the top is a wire mesh and has a big 10 inch fan under the center. there are so many on the market it is hard to pick one that shines over all others.