Good:
Their tea tree shampoo for 65p. I have fine, greasy hair and it stays clean for 2 days since I've been using it, rather than having to wash it every day like I have for years.
Their sliced bloomer (white or malted) is lovely! I wouldn't say it's all that cheap at 99p but it makes delicious tasty sandwiches and especially toast as it's cut very thick.
Their tinned chunky veg soup with minted lamb is divine. The chicken version is nice also but a little bit bland so I add a crumbled chicken oxo cube to it.
We had their frozen large stuffed turkey breast roast for xmas dinner and it was lovely - moist and tender, and a good ratio of meat to stuffing, unlike the 4-bird roast I bought from them a couple of years ago which tasted mainly of soapy sage.
I agree with an earlier poster who raved about their special selection treacle and coconut biscuits. I buy half a dozen packs at a time as my nearest Aldi is over 100 miles away (as is any supermarket except the Co-op).
Sliced Gouda and Edam cheeses - brilliant value at 99p for 10 large slices.
Frozen chicken breasts.
Stew pack of fresh vegetables. Huge bag compared to other supermarkets and lovely and fresh.
Bad:
Own brand cornflakes. Like eating cardboard.
Stollen bites. They were lovely in previous years but this year they were horrible. Dry, with a strange "sweetener" tasting coating.