2018 15" MacBook Pro (i7 2.6GHz/16GB/1TB SSD/560X 4GB) because I prefer macOS for the majority of my work, despite being able to work on basically any machine. The touch pad is still amongst the best I have tried, it's fairly reliable compared to the Dell XPS 15 I used to use, great build quality, and it integrates nicely with my other Apple peripherals. Realistically, I could get work done on about any machine since most of my work involves SSH'ing into different hosts running different suites of software in order to build kernels, drivers, and other configurations of OSes that get put on target hardware.