MacOS – Windows-Logo-Key + Left/Right Arrow — Keyboard shortcut equivalent on Mac

Ctrl-Tab and Shift-Control-Tab will have the same effect as CMD-ALT-← / →, and have the advantage of working in Safari, Firefox, and Chrome.

It's also nice to rebind them to function or gamepad keys so you can browse without contorting your hand à la emacs.

Here's how you can get ⌃ Control+arrow keys to work like you describe. Copy the following property list into ~/Library/KeyBindings/DefaultKeyBinding.dict (you can create the directory if it doesn't already exist):

{
    "^\UF703" = ("moveWordForward:", "moveWordForward:", "moveWordBackward:");
    "^$\UF703" = ("moveWordForwardAndModifySelection:", "moveWordForwardAndModifySelection:", "moveWordBackwardAndModifySelection:");
}

This will set up ⌃ Control+arrow to navigate to the beginning of the next word (by using OS X's normal navigation three times: to the end of the current word, end of the next word, then back to the beginning of the next word). I also included a version that works with ⇧ Shift so you can select text as you go.

Caveat: this will only work in Cocoa apps, but I think the normal ⌥ Option+arrow navigation does too. Also, make sure to relaunch your apps!