|I've had dicky knees for years, and started taking glucosamine on the recommendation of a doctor friend, I think that helped.
After a climbing fall when I mangled my ankle, my orthopod suggested that I should take fishoil to keep the joint mobile, so I started. I was pretty good with it and generally found that I was happy with my ankle and knees.
In January I went to NZ for two weeks, and forgot to take both my glucoseamine and fishoil tablets with me. After a week of the trip, we did a hike in fjordland. My knees in particular hurt more than they have for many years. It was only then that I started thinking about it and realised I hadn't been taking my tablets.
I got home, got back on the tablets, and I'm back doing my normal training walk/jog things up the Adelaide hills, and the kness feel 100% again.
In summary, I take both glucosamine and fish oil (you can get pills with both, but its cheaper to take them seperately), and without doubt, they keep my joints more mobile and pain free.
Currently I take 1.5g of glucosamine, and 4.5g of fish oil per day, but experiment with different amounts. My orthopod originally recommended a tablespoon of fishoil each morning. That 10mL (approx 10g). Unfortunately, the taste made me dry wretch, so I went to the pills. Even 3g seems to keep me moving well.