Notebook, HP, Dell or Lenovo?

Not really in term of hardware. But some maybe better in price, reliability and after-sales support. It really depends on individual brand liking on design factor etc.

Of those three, I would choose a Lenovo

You should check the specs (processors, hdd, ram, graphics, etc.), but personally I would not choose HP, even though they boast great hardware and performance. It all dependas on your needs eg. If you just need it for work, it would be useless to have 4GB of graphics, since you would only use that for gaming.

Hope it helps

The only thing you get from a brand name is support, meaning you would have to research which ones have the better, less haggle support if you need it. I don't need support so brand name means nothing to me. Every company has the gems and their duds, as a consumer you need to research each model to see what customers thought about it. Common problems would be poor battery life, cheap keyboard feel, and poor viewing angle of the screen.