Which laptop is better dell or lenovo?

Dell

In average brand reliability as reported by Rescuecom based on their experience, Lenovo is better.
http://www.rescuecom.com/...14-q3.aspx
Detailed info:
http://www.rescuecom.com/...#more-8411

However, exact models and specifications are more important a consideration than the brand label.
Lenovo and Dell do not produce the systems they sell, except Thinkpads which may be internally assembled.
http://www.xoticpc.com/laptop-manufacturers-really-makes-laptops-ip-11.html
Each model of each laptop will use different parts.

A G series Lenovo is quite similar to an Inspiron or an HP Pavilion or Acer laptop.

Dell!

Never heard of lenovo, so personally i'd go for the dell one. But just look at the reviews and features of the models you're looking at and make your decisions from them

Dell