Interesting thread! It will certainly bring out some stories.
I've owned vehicles across quite a few brands; Dodge, Plymouth, Ram, Jeep, Mazda, Toyota, BMW, Porsche, Subaru, Ford, Chevy, VW and Land Rover. Of all of those, the worst POS was the VW - 2006 Jetta TDI.
Other than returning phenomenal mileage (50+ mpg at 70 mph on the highway), it had too many engineering issues which VW refused to acknowledge. 1st was the dual mass flywheel (it was a manual trans). DM flywheels on TDI's were exploding quite commonly and owners were routinely told they didn't know how to shift a manual trans. VW finally issued a world-wide recall for that flywheel everywhere EXCEPT North America. The chattering on mine got bad enough to the point where I removed it myself and found the DM flywheel in the process of separating. Replaced it with the solid flywheel from a VR6 and problem solved, but I shouldn't have had to do that. 2nd, the camshaft actuated fuel pump, internal to the head (PD diesel) was very poorly lubricated leading to premature cam follower wear and scoring on the valve buckets, the injection pump buckets and on the cam lobes themselves. When I pulled the valve cover and found that, in its early stages, I sold the car with full disclosure to the new owner.
2nd worst was Chevy, and both of those were Corvettes; a 1988 and 1994 respectively. Too many issues to list, and these were Chevy's flagship model. You could not give me another Corvette, or any GM vehicle for that matter.
The Toyota, Porsche (911), Mazda's (RX7's) and Subaru's were flawless. The RX7's particularly were built like tanks. Don't know if current Mazda's still are.
The first few Mopars, 60's and early 70's models were good cars; built strong and designed to be easily maintained. The Dodge truck, 95, with the Cummins diesel, had a few issues which I had to sort like the death wobble (which STILL affects current Ram and Ford 3/4 and 1 ton 4x4's). I would still have that 95 but its rust proofing was terrible and was literally rusting off of the frame, and this was in N. Va, not the rust belt.
The other two Ram trucks were good vehicles, in general, however, the last, a 2017 1500, got very tired of trying to deal with the persistent valvetrain tick on the "hemi" engine. More than likely a poor quality part, such as a lifter from a supplier, but just didn't want to go thru the hassle of sorting it, as dealers only would say that noise is "normal", which is clearly BS.
First Jeep (Wrangler) was a good solid (95). 2nd, a 2003 was similarly good except it's crappy manual trans. Had to replace it at ~60k miles. The 3rd and last Jeep we will ever own was an ordered 2012 which leaked badly in every rain. Multiple dealer visits yielded only temporary fixes. Walking thru a dealer lot after a rainy night, I personally opened the doors of over 6 Wranglers with water on the floor. Got rid of that vehicle, said farewell to Jeep and have never looked back.
Am on my 3rd Ford. The first, a 92 Explorer started off great but had several niggling issues. The 2nd, a Boss 302 Mustang was superb. The F150 I currently drive is also a great truck.
Lastly, the Land Rover, our 2nd so far has been great. The first one also was great. Fingers are still crossed tho.