My college robotics course used Lego Mindstorms (back before the kit was discontinued) because it offered quite a lot for the price.

Our robots needed only to complete a simple task of finding the "reactor" (array of IR LEDs) on a 1x1m fenced board, but Lego more than delivered on the hardware front, because we had an IR sensor, an ultrasound proximity sensor and few other ones that we didn't even use.

Really helped to bridge the gap between theory and practice because it's one thing to program a servo motor and a completely different one to see your dead reckoning algorithm be off by a mile. Also sensors do a lof of things you don't expect.

Its succesor is named Lego Spike Prime, but I never used it, so can't comment.

IMO ever since the EV3, LEGO's robotics hardware has been on a downfall, being much less open and more focused on "connect it to your tablet with Bluetooth to do some basic programming". They also offer less ports and sensors and I think there aren't any custom sensors either. If you can find an EV3, it's the best thing you can get.