Totally depends on your mission / use. Handheld or base unit? Do you need digital trunking capability?
I use a BCT-15 for the Calvert scanner here on SOMD. It's a great unit, steep learning curve to program it but rock solid after you get it programmed up. It was about $250 purchased online, probably less now.
Most scanners these days can be connected to a computer to help program them, and Radio Shack scanners are pretty good. They offer a free pre-programming service as well.
I would expect most first-time scanner folks would be pretty happy with a scanner in the 100 to $200 price range.
BearcatWarehouse.com offers the best Bearcat scanners and marine VHF radios is where I bought mine. Many many other vendors though.