I love Aldi. Their only weak point is the produce--where I am, it's not as good. Don't get me wrong, it's not bad and is probably on par with most grocery stores, but we have Wegmans up here and nothing can compare to Wegmans produce.
Wegmans is inexpensive enough that it's allllmost comparable to Aldi prices, so I've started switching over recently, but honestly Aldi has saved our newlywed food budget for a couple of years and I can't sing their praises enough. Their frozen meat prices allow us to eat a lot better than we otherwise would and they're a great source of inexpensive snacks too, especially for nuts and chips. Their cheese/yogurt/guacamole are really good deals too.