I don't know what would meet my needs: the MacBook Air, or MacBook Pro or just the MacBook?
"Bangs per buck": iMac 5k
Extreme mobility: MacBook
Low cost & legacy connectivity: MacBook Air
What you probably want: MacBook Pro (non-touchbar)
The deal with the MacBook Air: it has a "standard definition" 1440x900 pixel display. Some people here act as though that will make your eyes bleed, but in reality it is reasonably good for what it is - but you can't get away from the fact that it doesn't hold a candle to Retina/4k displays. It has far better connectivity (with 2 good old USB-A 3.1 ports, Thunderbolt2/DisplayPort and SD card and
separate charge), than the MacBook, (and more
useful connectivity than the MacBook Pro if you're not planning to invest in Thunderbolt 3 peripherals or 5k displays). Consider if you're
mostly going to use it on a desktop connected to a large display and/or you haven't already spoiled yourself with a 4k/Retina screen.
The deal with the MacBook: incredibly small and light. Not really that powerful - but probably OK for your list. Lousy connectivity (only one USB-C port that
doesn't support Thunderbolt or USB3.1@10Gbps or
any USB3.1 alongside a 4k display). Good standard storage (min 256GB). Consider if ultra-portability is your top priority and your life is mostly wireless.
The deal with the Non-Touchbar MacBook Pro: really, this is the new MacBook Air and "mainstream" Mac laptop. Connectivity a
bit limited with only two USB-C/TB3 ports and adapters for breakfast - but that won't bother everybody and, unlike the MacBook, it
does support Thunderbolt 3 and USB3.1@10Gbps so there's some gain to justify the pain. Base model is only 128GB SSD, so be careful when comparing.
The TouchBar MacBook Pros also have higher-power CPUs with more grunt and are more deserving of the "Pro" label.
Used/refurb 2015 MacBook Pros are worth considering if you're not ready for USB-C to enter your life.