Rather than giving you a specific laptop, I will give you a strategy I have used for a number of years that has worked well for me. It allows you to have brand new equipment each year for less than what you pay buying a laptop and replacing every 3 to 5 years. I've only tried with Apple products.
- Create an Amazon seller account in which you have absolutely stellar reviews and customer service. A perfect five stars is what you are aiming for, which is pretty easy to accomplish if you try (e.g. with roughly 50 sales over the years, I only have one 4 star review and all others are 5 stars).
- Purchase the Mac product(s) you want.
- Ensure you keep good care of the laptops and also keep the original boxes and accessories.
- When Apple comes out with a new version, immediately buy the new version(s).
- Sell your old version(s) via your Amazon seller account.
Personally, I buy a low-end portable laptop (e.g. 12-inch rMB or 11-inch Air) and also a high-end laptop (e.g. 15-inch rMBP). You will find that the low-end of any product by Apple will retain their value best. However, even purchasing high-end (but non-customized) product is still pretty solid. This advice also works for iOS devices. On the whole, it costs me ~$750 a year to "lease" both the laptops. For example, I recently purchased a new low-end rMB for $1299. Given my seller account, I expect to resale the same laptop for ~$1099 when the new version comes out. So, I get a new rMB laptop each year for ~$200.
You will find certain product lines hold their resale value better. For instance, iPads, 13-inch rMBP, and both Airs hold their value well. On the other hand, iMacs and Mac Pros don't hold their value very well. In the middle you have iPhones, 15-inch rMBPs, and Minis. Customized add-ons (in which you can't go into a store and buy) are a huge no-no with this approach. The depreciation cost is just too high.
You will find certain product lines hold their resale value better. For instance, iPads, 13-inch rMBP, and both Airs hold their value well. On the other hand, iMacs and Mac Pros don't hold their value very well. In the middle you have iPhones, 15-inch rMBPs, and Minis. Customized add-ons (in which you can't go into a store and buy) are a huge no-no with this approach. The depreciation cost is just too high.