I always recommend building one yourself....but it all depends on your needs. Computers come in all shapes and sizes and are built to fit certain necessities.
I always recommend building a desktop pc over buying one, but when it comes to laptops, this is not easily done. This being said, as far as the business world side of things goes, Lenovo and HP are amazing at what they do and their devices are some of the easiest to support I have ever encountered.
for personal purposes, Lenovo does have a more streamlined set of laptops and notebooks, but they really are not cost effective for what you get, HP has a fairly good line of pc's for the regular end user who is not gaming, and for those of you who love to game. MSI or ASUS have some amazing gaming laptops(even though they are gigantic)that will do everything you want and more....but it will cost you for sure.
My opinions change a lot as well, so take my thoughts with a grain of salt....because again, just my opinions.