Robot-Coupe - R101BCLR

Forget buying attachments to turn another appliance into a food processor. The Cuisinart 14 as suggested by u/Fine-Sherbert-140 is the benchmark for serious home kitchen use. If you want to go nuts you can buy a commercial grade Robot Coupe that will last forever in home use. The original Cuisinart processors of 45 years ago were made by Robot Coupe. I owned one and it had enough torque to pull a train. After many decades I had to replace it because the plastic bowl eventually cracked and leaked with no replacements still available. https://www.webstaurantstore.com/robot-coupe-r101bclr-food-processor-with-2-5-qt-clear-polycarbonate-bowl-3-4-hp/649R101BCLR.html

Robot Coupe. Real professional grade machine. Second place, a Cuisinart Custom 14.

I'll agree on robocoupe and Hobart, but waring shit is garbage. I've seen two relatively new waring blenders and a food processor die from normal use and they all kind of sucked before they died.

A robocoup will last years. I worked with one that was dropped so many times the plastic that the outside was made of was cracked in multiple places and the safety didn't work, and it would still do anything I wanted it too

Unless you are VERY rough with your possessions, you likely won't need replacement parts. They are available from multiple places online and in person (restaurant supply stores),however. Though they are not cheap

Robot coupe or their residential side - Magimix A good ol’ cuisinart is a good choice too. The other box store brands are toys. Don’t even consider them.

This is the only answer. Everything else is trash by comparison. Unless like Vitamix makes food processors now or something, but I'd still 100% go with robot coupe.  There are refurbished ones available if they're out of OPs price range and honestly I would feel comfortable with a refurbished one. 

Agree with this. It is industry standard and Robot Coupe will also service it and provide spare parts forever. No need to worry about plastic bowls either. Stainless steel bowl. If you want a more domestic focused alternative, Magimix are made in France and very reliable.

Get an RC. Even when they break, they still work. It's worth it. 

The answer is always a Robot Coupe. Don't look at the price

This might not be realistic for you (I dunno your life/finances): Robot Coupe. They're pricey - if you can find a used one, they can be cheaper. They are generally made for restaurants who will use them heavily and the price reflects that. I bought a robot coupe food processor several years ago (I got a used one from a guy who owned a restaurant that was closing). It's hands down the only food processor I have owned that actually does what it's supposed to do. All the other ones are cheap underpowered crap, and I've owned a lot of them. Downsides: It weighs 27 lbs. You do have to replace the blades and bowl once every so often (my guess is once/decade). If you splurge on the metal bowl I think it will last forever. Upside: you will give this to your kids. Or whoever if you don't manage to make babies.