Hi Prem51, I did the same as you, and went "shopping" to check out varieties and countries of origin for those on sale in my 3 local supermarkets. I wanted to see which ones turn out best, and keep the longest, without going off. This is what I got so far:
Aldi: pack of 4 small (abt. 75g each incl. skin & stone) ripen at home. Hass - source: Columbia.
one went bad before ripening, so had to be thrown out. Second one was fine; not perfection, but good.
Aldi: twin pack of medium size (abt 150g whole) ripe and ready. Hass - source: Tanzania (that's a first!)
not ripe enough for me, so have yet to try one of these.
Aldi also had some single large avos, of South African origin, but I didn't get one of those, as already had more than enough!
Sainsbury's: twin pack, medium size (also abt 150g each), ripe and ready. Hass - source: Colombia.
First one was fine, just about right amount of 'ripeness', went down a treat.
Asda: twin pack, smedium size (abt 150g each), ripen at home. Hass - source: Peru
The best of the bunch so far, first one was perfect; hope the second one is just as good.
I suspect I might have overdone it on the stock / ripeness ratios and that some of them might well become over-ripe before I'm ready to eat them; but that's ok - maybe I'll have an "avocado fast" for the next couple of days
p.s. couldn't find any that were not Hass variety, perhaps that's all we get in the UK