I've been collecting the Ryobi 18V batteries and tools. I like that they continue to develop more powerful and longer lasting batteries that work in the tools I have.
I have about 4 drill drivers and impact drivers, a reciprocating saw, hot glue gun (best one I've ever used + cordless), work light, and even an electric caulk gun.
I probably have 6 or more18V lithiums with a variety of mAH ratings.
I've had 2 of the expensive "fast" chargers go bad. I just wait for the Black Friday sales with chargers bundled with batteries, and add to the collection. Always nice to have spare batteries sitting in a charger.
The last cordless tools I bought (last Black Friday) were the DeWalt cordless circular saw and oscillating tool. It uses their new FLEXVOLT 60-Volt MAX Lithium-Ion battery system. You can get cordless table saws and miter saws and use the same batteries as the other 20V MAX and 60V MAX tools. A circular saw may only need one 20V battery, but a table saw might need multiple 60V batteries. I haven't delved into which tools work with which combinations of the MAX batteries, but it appears the table saw needs 2-3 of the 60V to increase runtime to be useable. My circular saw runs on a single charge all day if breaking down a few pieces of plywood.
From what reviews I've seen, DeWalt has released a great series of products with these MAX batteries and tools. I do like mine,
As for the "AC/DC - corded - cordless" solution, you're better off using an inexpensive corded drill. They have more torque and higher speeds than most battery operated ones. You'd be losing the cordless advantages while also losing the few benefits of corded tools