First of all guys, ask yourself.. Do you want a laptop or a tower PC? I prefer a tower and a monitor myself. They usually perform quicker and are cheaper to buy. But it depends what your budget is and if you have the space at home. Yes laptops are great to carry around with you, but where is your working space exactly?
I personally invested in a custom built PC tower at least 3-4 years ago, funnily enough it still out performs some of the lower end computers built today. So good PC’s are normally worth the extra cost.
One of the key points to a good computer in architecture is the RAM. I would go for a computer with at least 8GB of ram, or over. If a computer or laptop has this amount of RAM the other specs will normally correspond to its performance.
Don’t forget the little things, a good mouse. And if at home, a good chair… Architects these days are prone to have back problems. Be one step ahead!
What brand? The company I bought my computer from went out of business a few years ago so I cant recommend them although they were very good! Macs are reliable but pricey. Check for warranty with the product if you can.
Most importantly do your research before you buy.
Best of luck,