I strongly agree that bare wire sounds best if possible. Some amps however, do not have binding posts that make it easy to use bare wire, especially if you are running a bi-wire setup.
The majority of terminations out there are brass with gold, silver or rhodium plating, all of which tend to degrade or change the sound quality and tone from that of the bare wire. A good quality real copper termination is hard to find, especially a banana. The only ones I found that I really like are sold by Douglas Connections. Don't fall for the fake "copper" connectors from China you may find on E-Bay. The Douglas "Furez" line of spades and bananas sound great, are not overpriced (around $60 for 8 ends), and best of all they have a version that you do NOT have to permanently crimp or solder to the wire, which allows you to re-use the terminations on any wire you choose, or switch between banana or spade for different amps and speakers! Here is a link: http://www.douglasconnection.com/Furez-TSTSB50NP-Bare-Copper-Banana-Plug-Connectors-Pair-FZTSTSB50NP...
The majority of terminations out there are brass with gold, silver or rhodium plating, all of which tend to degrade or change the sound quality and tone from that of the bare wire. A good quality real copper termination is hard to find, especially a banana. The only ones I found that I really like are sold by Douglas Connections. Don't fall for the fake "copper" connectors from China you may find on E-Bay. The Douglas "Furez" line of spades and bananas sound great, are not overpriced (around $60 for 8 ends), and best of all they have a version that you do NOT have to permanently crimp or solder to the wire, which allows you to re-use the terminations on any wire you choose, or switch between banana or spade for different amps and speakers! Here is a link: http://www.douglasconnection.com/Furez-TSTSB50NP-Bare-Copper-Banana-Plug-Connectors-Pair-FZTSTSB50NP...