Really what ever fits your budget! There are radio's out there that are field programmable, which is nice since you can change your frequencies when you want. Some radios like Kenwood, Vertex, etc., the software is out there and lots of it is free. Motorola makes some real solid radios (older radios) such as Saber, HT1000, MT1000, MT2000, but you have to buy the software (of which since the radio's are no longer supported, good luck on finding it), a RIB (Radio Interface Box), cables and you will need a SLOW computer (read P100 or less).
You can also buy a lot of these radio's off of eBay and the sellers usually offer free programming.
Good luck with your search!