For a complete cleaing and some what of a restoration, I like to use Leatherrique. It has worked wonders on some of the worn out leather I have encountered. My all time favorite for standard leather care would have to be the two Zaino products. The cleaner really helps to get stains out and the conditioner really brings back the smell. I also have the Lexol products and the cleaner works great due to the amount of water and foaming action. Not a fan of the conditioner at all though.
Danase leather has a great smell and I usually get a lot of dirt on the MF applicator. For some reason I just don't think it gives me the look I am going for.
1Z Leather phlege seems to do a decent job also. I like it's cleaning ability but don't know if I really like the smell of it. It kind of has a perfume to it that lingers in the car. This perfume matches well with the interior of a Rolls but really doesn't go well in most other cars.
I really like the UV protection of 303 but leave that to the trim and other plastic pieces. Some of the lower class Benz's have lots of Plastic and rubber that get 1Z or PB restorer and then topped with 303. I just don't like to use it on the leather seats. It just kind of reminds me of the days of Armor All.
Meg's has had tons of leather care products. I have used GC spray many times and have had great success with it but don't use it anymore. I have also used many, many, many GC leather wipes. If you like that Armor All look, definitley go with the wipes. Sometimes I still break a canister of these wipes out on certain cars for that look. I tone it down a bit by wiping over it but have never had any bad experiences.