Honestly, just shop around and find something in your price range from a quality manufacturer. I based my requirements more on appearance than anything else, but did get a middle of the range unit. I believe I bought a Kenwood because it was one of the least flashy units available - limited chrome bits. I wanted something that would blend in fairly well with my stock dash. Do get an installation kit with the correct adapter for your car, it will make it much easier to install since you can do all the soldering/crimping on the bench, and you shouldnt need to modify your cars wiring. You might want to upgrade your speakers at the same time. Unfortunately my w123 only takes 3.5" and 4.25" speakers stock, so I am fairly limited in the sound quality I can get. At some point I plan to install a sub/amp combo unit under the seat to try to get a reasonable amount of mid/low range.