We have done the market research!!! Rufus is a total power chewer and loves his toys so I'll post my list!
Generally, simple round balls are better than angled toys.
Orbee tuff balls: great. Not totally indestructible but will stand up to constant chewing for quite a long time. Worth the money for Rufus, definitely! they are also light so can be thrown in the house and are hollow so you can fill them with treats, which we do quite often. You can get them at The Dog Web in the UK
http://www.thedogweb.co.uk/catalog/index.php?cPath=24&osCsid=36f2e762c1f197ba23a5c7089d498c06 and Planet Dog in the US. Rufus loves his Orbo and the round fetch and woof balls. He's chewed those like crazy and still going strong! We also have the large globe ball which is good for filling with treats.
Kongs: brilliant (only the black though) and for Kong toys, again the round solid Kong balls are fine but all the other kong toys can be torn apart (the red ones) in short order and in little pieces so they end up making a mess. Rufus has the XXL black kong that we fill for him when we go to work. He's not even made a dent in that one.
zogo-flex (hucks): we're trying those out. So far, so good. I got them from
http://www.houndsaroundtown.com/fun/huck.html in Canada.
Nylabones: Brilliant - Rufus particularly loves the red and yellow puzzle one. He spends a lot of time everyday chewing on his various nylabones, of which he has at least three different ones at any given time. I got those at Pets at Home but pretty much any pet store will have them.
We have an old tyre in the back garden that he likes too. He goes to town on that one!
Boomer/indestructi-ball: he likes this the least of all his toys because he can't get his mouth around it. He's so not interested in just pushing it around.
Tuffies: even the tiger tested one was no match for Rufus. He found the weak spot and systematically destroyed it within 10 minutes. You can check them out here
http://www.woof-world.co.uk/index.php?main_page=page&id=1 I don't give him anything with ropes, including the big chew ropes because the first thing he does is chew through it and then what he has ingested gives him the runs. Same with stuffies. I thought the Tuffies would be great but no such luck.
Water bottles are limited fun - if he finds one on a walk, he'll carry it in his mouth happily but if I give him one at home, he destroys it within minutes. Same with tennis balls. Out and about, they're great but at home, given a chance, he'll have it destroyed within minutes. Still, I will put treats in a water bottle and let him go to town, occasionally.
Any squeaky toy is toast as soon as Rufus gets a hold of it. He acts like he has to annihilate it and get to the squeaker as soon as possible! I'm waiting on an order from canada for Sqwuggies which are made from old fire hoses. (you can check them out at Hounds about town - same place for hucks)