If you freeze fish to death just so the fish tastes better, I consider your act inhumane. If you think that's fine, you're entitled to your opinion.
Here is some information I found on how to keep your catch fresh:
[FONT=Verdana, Arial, Helvetica, sans-serif]"Proper care for your catch in the field will go along way toward ensuring it tastes good and fresh when it eventually gets to the dinner table. Contrary to popular practice, keeping a fish alive on a stringer is not a good idea. You should kill your catch quickly with a sharp rap on top of the head. Blood in the meat of your fish will greatly effect the freshness of its taste so bleeding your catch by cutting the main artery to their gills is essential. As much as possible, it's also a good idea to avoid letting your fish lie in water, blood or slime after cleaning. However, if you plan to continue fishing for some time, uncleanned fish can be kept cool in the river while you complete your limit. Once you're done fishing it's always a good idea to cover your cleaned fish with ice to keep them cool in transport to the processor (or your own freezer). Avoid throwing or dropping your fish as this can cause the meat to bruise. Particularly with salmon, filleting and vacuum sealing your catch in 1-2 lb. portions seems to work best. Vacuum sealing and freezing your catch will go along way toward preventing spoilage. [/FONT]"