We owned three Buick Regals with 3.8 l V6 of various vintages. The first two were the least troublesome cars we ever owned and we gave them away for free at more than 240000 miles. The last one (1999) has 140000 and is not as good as the older models.
I rented LaCrosse hybrid about six months ago and I was quite impressed with the car.
We owned several Japanese cars such As Nissan Sentra, Honda Accord, and Subaru Outback. All of those were OK to about 150000 and then just fell apart. Nissan had transmission noise and later on suffered complete tranny failure, Honda Accord rusted and had engine issues the dealer was not able to fix, Subaru was $100/month in repairs such as leaks, sensor failures etc. We were quite happy to get rid of it after my wife reaerended a pickup truck.
We bought our first used Buick (in 2000) after I got a contract job at Buick assembly plant and saw how they were made. Even the powerhouse (that is usually a mess in car assembly plant) was nice, organized and clean. Here is a story I heard: The plant got new manager who came from military. The first thing he did he took away golf cars from the foremen and supervisors. Reason being they just cruised trough the plant and didn't talk to their people about issues.