most of their power or battery tools are lifetime warranties IF you register it within 3 weeks, and that includes batters as well. I'd go with Ryobi for tools that you don't plan to use a lot of. Ryobi isn't a bad tool... just don't expect it to last a long time and under constant use. And I'd say Ridgid tools are pretty close in quality to Dewalt tools.
As for hand tools... get Husky tools... they are lifetime guaranteed. If it breaks on you, like a socket wrench, you just have to bring it in to any Home Depot without the receipt, and they'll give you store credit towards a new one.