Being English, we love our tea. I drink about 10 cups a day and there is nothing better than having a good biscuit to dip in. I eat mostly burbons and custard cremes, I also have some Oreo sometimes but they taste a bit artificial. I can't really explain what I mean, but there is something a little odd about them. What biscuits can you recommend, I will pick some up off your recommendation and let you know what I think when I get time.
I like to eat little Danish cookies (the kinds that comes in large tins) with my tea or coffee, or get the cookies that they sell at my local bulk food store. I'm not sure of the brand name, but they have a nice selection. I like the ones with peanuts or almonds on top, as long as the nuts don't fall into my drink. You can also try Dad's oatmeal cookies because they turn nice and soft upon getting dunked; those come in a yellow box. Maybe your problem with the Oreos is the cream filling? Personally, I can't stand the taste of it, and it does make everything excessively sweet.
I'm in the US and so I'm not particularly used to eating cookies (or biscuits) with my tea. I just drink my tea plain, no sugar and milk or anything. But if I'm having like an afternoon snack or post-dinner dessert where it's sweet, I definitely prefer something sweet with my tea. If I had to pick though, I think anything shortbread would be awesome. Shortbread with some chocolate on it is best