Somebody recommend a serum for me?

[BarrackerBarmer]

After years of not bothering at all with my skin, I've recently started using retinA at night with a moisturiser. (I really don't enjoy moisturisers much at all, I must say)
During the day I've just finished a vitamin C serum and also a I-Bought-This-serum-In-TKMaxx-because-its-RRP-was-£100 serum, which I was using in the morning. I'm surprised to say that my skin does actually look better for it, so I thought I'd look for another vitamin C serum and/or something else to see how I get on.

I've heard good things about the Ordinary. What would people recommend as a starter vitamin C from them, as I believe they do several?

Should I add anything else in too? I'm using the cheapy Aldi Cuvee serum right now. Not really sure what I think of it.

I recommend the Caudalie vinosource sos serum - so moisturising but not in a sticky tacky way. My skin seems to just drink it up. It's around £27ish from space nk.

The serum I have liked most so farfrom the ordinary is the hyaluronic acid. I wear it in the day, I don’t need moisturiser anyway. I wear it at night with rosehip oil or retinol.

Thanks both - have you tried a vitamin C that you would recommend?