Personal comfort preferences:
The AF version of the A330 is my absolute favorite plane to fly for anything longer than 2 hours. Even the coach seats are moderately comfy for a x-atlantic flight to Paris. My other fav is no longer in service - the L-1011. Nothing like a J/F class trip on one of these. For a single aisle, I like the 2 side of an MD-88 if I have to ride in the cattle car, otherwise it's a 737-800 for F.
Personal engineering preferences:
Most any heavy designed by Airbus. I'm an engineering technology consultant that visits both companies ... and based on what I "haven't seen" while conductin business ... this really isn't a contest here. Sorry to say this, as I grew up in Seattle and the great Boeing empire. As for manufacturing paractices, I can't say as I never visit this segment of the companies.
GMF