lol... the Sony MP450 good? HAHA! damn you gotta research some more. Some of the better ones for the price are the Clarion and the JVC. But if your on a tighter budget, go with the Jensen 5010K, it is better then the Sony and slightly less expensive too.
Trust me, I've been lookin at these for the past month or so, to find a good one, so far I'm hooked on the JVC and Clarion. But that could change, all of these receivers I've seen first hand installed. I dont suggest buying the Sony or the Jensen, 3 weeks ago, I would have said, Jensen, but now after thinking about it, it's better off spending a couple more bucks then having limited features, such as no EQ, bad visibility of HU during the day when driving, and limited RCA connects. Also with the higher end HUs you'll get many more fetures, one of which I liked is the AUX out, allows connection of whatever you like, to be controlled straight from the HU.