I'm as guilty as anyone of getting useless kitchen gadgets, but was thinking about what I've used more Than I ever thought I would.
I was given a cast iron frying pan years ago which I was underwhelmed with to begin (heavy, food seemed to stick) but now is my most used kitchen thing ever. Non stick from several years of use can take any amount of abuse (steel wool, burning etc) and end up as good, if not better than before.
Other than that, my kenwood chef (used much more than my magimix).
Only gadget I really use is my thermapen thermometer, really handy for chocolate / caramel / jam and for meat joints (no more overcooked Sunday roasts). It was expensive but worth it.
What kitchen tools are indispensable to you?