BFA bananas all the way. they have solid contact all the way around and into the terminals and have a very strong grip. there are various types of attachment. i use nerve audio on ebay.. i buy copper sleeves to put over them and crimp the crunk out of them. it's a very secure connection.
http://www.ebay.com/itm/Nerve-Audio-Silver-Ultra-Low-Mass-BFA-Banana-Z-plug-Connector-DIY-Set-of-4-P...
i also used these once. audioquest. they came with crimp sleeves and were even more solid, but also bulkier. but you don't have to search for copper crimp sleeves.
https://www.musicdirect.com/connector-upgrades/audioquest-crimp-bfa-bananas-set-of-4
either way, check out BFAs. more contact area than a spade and stronger spring force than regular bananas.
http://www.ebay.com/itm/Nerve-Audio-Silver-Ultra-Low-Mass-BFA-Banana-Z-plug-Connector-DIY-Set-of-4-P...
i also used these once. audioquest. they came with crimp sleeves and were even more solid, but also bulkier. but you don't have to search for copper crimp sleeves.
https://www.musicdirect.com/connector-upgrades/audioquest-crimp-bfa-bananas-set-of-4
either way, check out BFAs. more contact area than a spade and stronger spring force than regular bananas.