If you're asking about brands they both have good and bad products in their lineups but since all brands have multiple SKU's in their portfolio, which laptop are you referring to in terms of them being good or bad?
Some Dell laptop in the past had a bad spine/hinge design that gave way after about 1 year of use. Likewise, cheap laptops are often times the one's you should avoid.
If you're asking for guideance on what laptop to buy as a replacement for the one you have, then please stylize your thread with info stylized like this thread;
This form makes it easier for us to recommend you a laptop, so we don't have to ask you lots of questions. Please copy and paste these questions into the thread you post, and we can help you find the laptop that suits you. 1. What is your budget? 2. What is the size of the notebook...
forums.tomshardware.com
as a followup post in this ongoing thread.