For retail products I know Olay is currently topping the charts in results seen by those who've tested their products. For non-retail products, Mary Kay tests best.
Personally, I've been using Mary Kay products for 16 years and I 100% credit their products with my skin looking as good as it does, given that I'm 37, have a child, a stressful, full-time job and that I don't exactly do everything right for my skin and body (like proper nutrition, exercise and keeping my skin care routine on weekends). I'm sure someday I'll wake up with wrinkles around my eyes and mouth, but for now, I'm hoping to ride this wave until I'm at least 45!
Regardless of what product you go with, know that any product meant to help with the signs of aging takes time to see results (usually studies are a minimum of 12 weeks). So start something and stick with it for a while. If you need any Mary Kay samples, let me know. I became such a good customer, I eventually decided I wanted to become a consultant in order to get the discounts. I order the samples to take with me on business trips, so I have a few on hand.
Good luck!