Not all vitamin Cs are equal (read more on gettiing to know the various types of vitamin C
) and ascorbic acid is one of the least effective because it isn't stable (it starts to evaporate the minute you open the bottle) and it can be very drying. The Perfect C Serum ($31.2: $10 below the usual price at Amazon.com) caught my attention because the name is so outrageously self-confident and also because it is by Mychelle, which is such a good brand that it might not be mere hyperbole.
Mychelle claims to have stabilized the L-ascorbic acid and has used it in a hefty concentration of 17%. The vitamin C is coupled with d-beta glucosamine, which (as far as I can tell) usually comes from foxgloves and there seems to be some good evidence that it helps to build collagen.
Apart from water, the base is hamamelis, extract of date palm that is a good moisturizer and should, therefore, help to counteract the drying effect of such a high concentration of ascorbic acid. Nevertheless, Mychelle cautions users to be careful applying it around the eye area. In fact, I don't think I would since there is also some retinol. Mychelle has added some good anti-oxidants in the form of wine phytoalexins, CoQ10 and beta-caratene.
I am a fan of Mychelle's products, but this one may be too harsh for the sensitive of skin. An alternative could be Isomers Laboratories Vitamin C serum ($39.99). Isomers uses a form of vitamin C called MAP (Magnesium Ascorbyl Phosphate). This is not the most potent, but it is stable and it is a great option for sensitive types because it is not acidic. Isomers has pared MAP with vitamin E. Depending on the concentrations, which Isomers doesn't specify, this combination is potentially a good anti-ager. Apart from linseed oil and a couple of parabens, this potion is unadulterated C and E.