My vote is that you can't go wrong with a Marlin 336 in .30-30 as you can pick one up fairly inexpensively and if you like it go from there and get the big medicine - a Guide Gun in .45-70.
Just watch the Marlins produced when Remington first bought them; they are a little iffy in the QC department and some had issues. I think they bought them late in 2007.