Bump - I can relate. My wife and I were just in a similar situation. The 99 you see in my sig was getting old, had a boat load of miles, and needed some repairs. We were both ready to graduate out of the Bonnevilles, but didn't want to spend a lot of money.
Surprising as it may seem, the Ford Crown Victoria/Mercury Grand Marquis got very high reviews by all the notable online reviewers (edmunds, MSN autos, etc.) and are quite affordable. The 2000 Mercury GM in my sig cost us only $6200 and has only 40,000 miles. You'd be hard pressed to find that kind of value anywhere else. Plus, being the same drive train used in taxi cabs, police cruisers, etc. they're very durable! Just like all domestic cars, they depreciate like a rock, but live a long life. According to all the reviews I've read, there'* not one common failure point. And, being a full framed car, they get a 5-star crash rating. Means insuracnce is dirt cheap (full coverage costs us $293 every six months).