At the absolute cheapest end of the market I'd give Sony a miss. Their absolute entry-level models are traditionally pretty shaky - last year's S5500 and previous year's U-series sets are great cases in point with the former experiencing all sorts of issues that never reared their head on the rest of the range. The sony range always seems to start properly with the V-series/EX403.
I'd be tempted to give the LG strong consideration for a budget buy. I've got a 4 year old LG 26" LCD in a bedroom. After sitting there doing nothing in a spare room for ages I've recently set it up again and been really impressed with it.