I guess Ive been quite lucky with medion in that Ive bought a few of their PCs, because the spec was cheaper than I could purchase parts and build myself for. There were a few of us on here at the time who just couldnt self build for the price of their whole package. PDA's and sat navs have also in the past been good.
However Ive had one of their TVs that went straight back.. and their keyboard/mouse combo's arent up to much.
At least Ive found that Aldi are quite happy to give you a full refund if not happy.