I like their deli products - lardons, continental cheeses.
I also like their pasta sauces.
Their coffee is a bit rough, but manageable for a pound a packet.
Juice and fizzy (or still) water is a giveaway.
Their biscuits are good, but I try to show restraint. And also their continental sweets.
Fresh flowers - a bargain.
I only really go to Aldi/Lidl when they have a special that I am interested in, and I tend to pick up the above when I am there.
Their fruit & veg is good value too - all class 2, but still cheaper than you'd think.
Their household products and personal hygiene products are cr@p, IMO. Their wine is too rough, even at £2 a bottle. Cereals don't pass the child test.