What's the best thing to give my older dog with arthritis?

Wuffy too has arthritis. I agree with everyone else. I would like to add two more points my vet said. One, keep her weight down. Don't let her get overweight. And manage the heck out of her. She not a puppy anymore she can't run as fast or play as long. You have to know when it's rest time!!

We have given our Bassets Glucosamine/Chondrointin for awhile now and it really seems to help. They need a supplement daily to be effective. When they seem to be in more pain than usual we give an aspirin, we've used Deramaxx but only when absolutely necessary because the aspirin works fine for day to day aches and pain, and you don't really want them on pain meds for an extended amount of time unless absolutely needed.

Arthritis can also be treated with a change in exercise regimen.
see www.physipet.com
This may be able to help get him back active, and keep his joints moving and getting stronger, naturally.
Just as another option..

My German Shepard takes Deramaxx. He does very well with it and it is inexpensive. He is about 85 lbs. and it costs me about $1.50 per day.

We gave our dog rymadil and rejuvenate and towards the end there was another medicne but I forget what it was called. It wasn't cheap but made a tremendous difference for over a year. We just put him to rest a couple of weeks ago because it was getting so bad that he started snapping at the kids (we have a 5yr old and a 22 month old) and left some bruising and broke the skin a couple of times when he thought he was going to have to move. It was really hard. Had it just been my husband and I or if the kids were older we would have tried to do more. Good luck!