I started with an entry level 9 gallon pot that was a 'scratch and dent' from Austin Homebrew. Over the period of a few months and a half dozen batches I added a kettle valve and a sight glass/thermometer combo from Brew Hardware. Quite pleased....
....until I decided to try BIAB and wanted the capability of doing high gravity beers or 10 gallon batches. Hello Blichmann 15 gallon Boilermaker
Built like a tank and I'll pass it on to my heirs when I die. Pricey, but I don't regret it. Just getting the last of the parts I need to turn it into a gas fired BIAB RIMS system, I love being a engineering geek almost as much as brewing.