I forgot my best:
#1 best built car I owned was a 1990 Mercedes 190E 2.6. I thought this car would be a nightmare when I bought it, as the six was so crammed in, I feared working on it. 510,000km and it finally got donated to the Kidney Foundation thanks to the suspension all finally giving out. Everything on the car was original, including the engine, trans, final drive, shocks, springs, and so on. The interior was perfect and the body was rust free except for a minor spot where I had a bad door ding. The A/C still blew cold. For "major" repairs, the car had had an alternator rebuilt (you could rebuild them!) and a thermostat. That's about it! The body was solid and NOT ONE squeak or creak in over a half million kms.
#2. Would probably be our current 2001 Subaru Forester. 300K and the engine uses not a drop of oil, the trans shifts like new, everything except the clock works perfectly (I'm too lazy to fix that) and mechanically, it's been very solid. Thanks to being very rough on it, it's had some bits replaced, but considering the abuse, it's been way more solid than I expected. Two front struts and both front axles, a blower motor, a starter motor, and the other day I replaced the power steering pump ($69 for a rebuilt unit!!) and otherwise, just routine service. One of the front axles I damaged while on a so-called "road" a few winters back in B.C. that also scraped the crap out of the underside, but no damage past the axle. There is some rust around the left rear wheel well that wouldn't be there had I not ripped the plastic shield off when on another "road" where a broken tree caught the body there. One of the rear struts is weeping a little, but has been doing that for about a year and seems to just stay the same. However, as solid as this thing is mechanically, it rattles enough to drown out the radio.