I have both a fixed VHF (just inside the companionway to port) and a handheld.
The fixed one was in the boat when I bought it. While it is easy for the mic to reach into the cockpit it is hard to use for 99% of what you want a VHF for which is listening. Turned up loud enough to hear in the cockpit it bothers everyone else on the boat, particularly those below.
Because of this we bought an inexpensive handheld to use at the pedestal. It is the only VHF that has been turned on on my boat for the last 3 years. It drops easily into a cup holder at the pedestal.
While a handheld has less power, and with it's small low antenna less range, we have found it has met every need we have. As I said, most of the time you are just listening anyway and it receives local traffic just as well as the fixed unit. It's worked great for the few conversations we have had, mainly calling ahead to marina's to get slip assignments. We did talk to the Coast Guard once to get instructions on how they wanted us to go around the Trident sub they were escorting.
A VHF is not Coast Guard required equipment. On our recent inspection by the Coast Guard they did not ask at all about a VHF. Still, everyone should have one on board for safety purposes, preferably one with DSC capabilities connected to your GPS.
There are a few handheld DSC capable VHF's. There is one with an internal GPS so it always has your position, and a couple others that are connected to the GPS when they are in their cradle which could be located at the helm. If I were buying again I would look for one of the DSC handhelds, particularly if it was going to be the only VHF on the boat. Having the DSC capabilities greatly enhances it's contribution to safety in an emergency situation. It seems silly to me that every handheld VHF made doesn't have a GPS receiver in it like all the current cell phones do.
No license required, if you do get a DSC one you have to register your MMSI. Not only is it the ID used for distress calls but it is essentially the phone number for your VHF and can be used for other purposes besides emergencies.
Good reading
http://navcenter.org/marcomms/boater.htm
http://navcenter.org/marcomms/gmdss/dsc.htm
http://navcenter.org/marcomms/gmdss/whydsc.txt