Both are good, personal preference. But, you are probably right the spade connections would generally have better physical clearance for on-the-wall configurations. Banana connections would normally be more secure becuase you don't have to screw them down like spade connections.
Some thoughts:
(1) first make sure your connector is very secure ( the newer screw-on types are very good) on the wire.
(2) then you need to make sure you terminal connection is secure. The only negative thing about spade lugs or spade connectors is that you have to make sure your speaker terminals are very tight (good hand tight). If the speaker terminals can unscrew all of the way then then a ring terminal connector is the best!
here is an example ring terminal connector
http://www.wiringproducts.com/index1.html