I can't make my mind up as I really only want to go for one as I'm going to place this within the page titles
Ta
Tig's
P.S I presume this post won't get any replies as everyone is out doing last minute Xmas shopping
Plural is usually used in either case which wouldn't make much sense on your pages if only one shop/store.
In addition, I also think this is a culture thing much like the US use "shopping cart" and UK usually use "basket" which could also be broken down by age group, or quality of living (e.g. upper, middle, or lower class).
Probably market/industry dependent as well.
Personally I would stick with titles that reflect generic product(s) names of the page rather than an action/place.
If it was a rather large site or the "brand" included Shop or Store - might go the other way.
According to the numbers even split but plurals are the clear winners.