Nate:
I have a cardboard box of vhfs in the basement. Of them all, the ICOM M72 is the one I reach for (or already have in my go bag), and the Standard Horizon 270 is the one I loan to the other captain.
If your expectations are modest, any of the various $100 hand-held Cobras, Humminbirds, Unidens, etc. will be OK, in kind of the same way that a $15 rechargable spotlight is OK. We use them for chattering between layouts and tenders. But in foul weather or after a couple hours, they go away in a hurry, and that ranges from damn annoying to dangerous, depending. For keeping track of multiple parties spread over long distance, or emergencies, I wouldn't want any of them to be my sole means of communication.
If you want a radio that's more pleasant and reliable, Standard is good, hell for stout and priced right; Icom gives and gets better reception but they are spendy, especially their itty bitty radios. Both of them are, at a minimum, twice as useful as the other brands mentioned above.
Whatever you choose, insist on Li-ion batteries versus any other. Battery life in a handheld is more important than you might think, because performance goes to hell as the batteries discharge. For this reason, the slightly larger, midsize handhelds (with their larger batteries) suit my needs better than the itty bitty radios. They work better with heavy gloves on, too. My M72 needs to be charged less often than my dad's M88, and it's about $100 cheaper too. On the other hand, a radio's like a pistol, doesn't do you any good if you're not carrying it, so the smaller radio might work better for you.
Cabela's and West Marine both have good deals on private-label radios made by Standard if you're looking for a bargain. I wouldn't hesitate to buy either one. The one Cabelas has in particular looks like a good deal.
Pete's right that none of them will give you the kind of range (or big-ass 12v lead-acid battery life) of a console radio with an 8' antenna. The M72 at 6W comes closer than any of the others though, we have no problem raising each other over 4-5 mile expanses of open water, as long as both parties have good radios. And it's awful comfy to have it clipped to my vest should I be separated from the boat.
For the ne plus ultra in versatility, it's possible to get a mast antenna setup with an adapter that will allow you to connect your handheld to a big auxiliary antenna. I imagine this would give you significant improvements in range, especially in terms of reception (for transmission, there's only so much antenna a 5w radio can drive). But I have never felt the need to do so.