We hooked up via composite to a standard definition 20" LCD TV, a standard definition 30" CRT and a high definition 26" widescreen LCD panel. Frankly, the 360 looked atrocious with the composite. Colours bled everywhere, games were upscaled horrendously... the whole visual experience was frankly no better than the first Xbox. We'd go so far as to say that if you are limited to hooking up your 360 via SCART or composite in standard definition (eg with a 'normal' TV), don't even bother buying it. It looks bad..
Read on over here.