There are plenty on the market . If you're just looking to pick up air traffic control any of the cheaper Radio shack models will do. My Radio shack Pro97 worked just fine. The voltage converter was a pain in the ____ to use.
Sadly Radioshack scanners aren't available here in Ireland.
If you're after Airband, there's plenty of choice. Almost all Uniden models can pick up Air Band, and are by far the most popular scanner in Ireland (although many of them can't be used with a computer), namely the very popular UBC72xlt and UBC92xlt.
For a computer connection I recommend the AOR AR-8200 if you've got €400 to burn. It can pick up almost EVERYTHING in use in of Ireland or the UK, except the digital TETRA radios of the Gardai and UK Police.