I'm a mac user for years now. I currently use the 2011 21.5" iMac. It's very useful for me because I'm a musician and a songwriter so it definitely is a necessity for me. Its apps are perfect for my profession.
Since most of the time I build my own computers, I don't really have a go to "brand". If I had to choose though, I would have to go with ASUS. From what I've seen with their company, the computers really hold up well in durability and processing power. I would highly suggest them to anyone.
If you have or want a desktop, you should really build your own. That being said, for laptops it really depends. I'm more fond of Lenovo for portable, classroom/business type use and ASUS if you want to have a portable desktop. Lenovo in my opinion make good products cheaper than the comparably powered competitors. A part of that is that the company is based out of China, but they do their job much better than Sony.
I have a Lenovo laptop which I'm very happy with. I also own a Dell computer and it still runs well, even though it is almost ten-years old now. I need to upgrade my PC or just buy a new one, you can buy a decent one for around 400 dollars nowadays.