I am personally intrigued by the Hornady LEVERevolution ammunition. I am patiently waiting for the components to become available to the handloader.
The bullets should perform well in the new Marlin 1895XLR (45-70) with its 24 inch barrel; however, as mentioned earlier the 450 Marlin (Marlin 1895MXLR) would be a good choice also if you do not have a stockpile of 45-70 brass already.
http://www.marlinfirearms.com/firearms/xlr/1895XLR.aspx
http://www.marlinfirearms.com/firear.../1895MXLR.aspx
I haven't had the opportunity to fondle one of these rifles yet, but I am looking forward for the chance to do so.
Another one or two to put on "the list".