Lenovo don't really make computers. HP don't really make computers. Sony don't really make computers. All any of them do is to assemble components made by other firms.
In practice they early all use either Intel processors or AMD processors, so there's very little to choose between them (although, of course, both Intel and AMD make 'basic' processors for, say, office computers and 'super fast' processors for things like gaming - you need to get the right
type for your needs but the actual make is largely irrelevant).
So less well-known brands of computers are often as good as the big names. (In particular, the Medion computers which Aldi periodically offer are usually well-reviewed and offer excellent value for money).
However avoiding Lenovo might still be a good idea because they've recently been caught out selling laptops with malware pre-installed!
http://www.bbc.co.uk/news/technology-31565368