I'll add Yogi Bear to this list. Yogi is 12 years old. He was a rescue, at the age of 5, from deplorable conditions in southern Ohio. When we rescued him he was 130lbs, and now, he's about 155 when his thyroid isn't acting up. He is a sweet old bear, though he still doesn't like to be groomed much. I've recently stepped up my efforts (which now include a muzzle, mesh not leather) just to remind him "i'm in charge." He loves loves loves my husband, he love love loves my daughter, and when no one else is around, he occasionally, loves his mother ;-).
He is a great old boy, and while he spends most of his time "holding up the floor," he does still find energy for a romp (about twice a week) and we do take small walks every day to and from the bus stop. I'd like to walk him further but his back hip joints are really pretty stiff most days, and I don't want to put him in any extra pain.
Curiously, he's not much of a swimmer. He /can/ swim, he just elects not too.
For a dog that was labeled as "must have fence," and "no children," he has done remarkably well. He's only "bitten" once, and that was a disagreement last week with my husband about some garbage. Yogi lost. Tee hee.
He is slowly adjusting to life as an only dog. He sleeps in all Cordy's old spots so I know he misses her as much as we all do. He doesn't really know about our plans to add another nearly senior Newf and probably a puppy as well this summer, but ... he'll take it in stride, I know he will.
He is a protector as well, and has scared off more than his share of salespeople, custom agents (yes, seriously) and trick-or-treaters. ;-)
Ah ... the life of a senior Newf.