My favourite is not the best vehicle we've ever owned, so I'll break those out separately:
1. Most reliable/best vehicle: Our 2002 Ford Expedition Eddie Bauer - Thing was an absolute tank, we sold it privately after picking up the Durango. It is still being driven, it appears the new owner has done the body work (rockers were rotten) to get it through a safety. Thing ran like a million bucks with 300,000Km on it, and seems to be continuing that tradition. Bulletproof drivetrain (5.4L 2V backed with the 4R100, tow package with aux coolers and skid plates).Notable issues during ownership include front suspension bits, which were replaced with Moog, which solved that, and it launched #4 spark plug which required a lock-n-stitch insert in that hole. No overly expensive repairs, never left us stranded (drove it to Ford with the launched plug) and the best vehicle in snow we've ever owned. It was driven hard and held up incredibly well.
2. Favourite vehicle: My 2001 BMW M5. It was quirky, and repairs were on the expensive side. I traded it on the SRT Charger when I got mad at it for needing an entire driveshaft because you couldn't put U-joints in it. Held onto that for a year and flipped it for the Jeep. Jeep is my 2nd favourite, and certainly massively more practical in a two-vehicle family with three kids.