If you're buying new cables, check out the bluejeans. I really like their locking banana plugs.
I'm leery of any locking or extra-tight fitting connector. It's too easy to mess up the jacks on your gear with them.
On the amp side, I just use dual banana plugs like Wayner mentioned. The ones I have are gold-plated Pomona clones from Parts Express.
On the speaker side, I had to go with single banana plugs, and they're also from PE. They didn't have suitable insulated ones, so I had to go with "audiophile" ones with plenty of exposed bare metal. I don't have small children, so I can get away with it, but I'd much rather have insulated plugs. (All my binding posts are insulated.)
