The Arhoolie label has released a lot of good, well-recorded blues over the years (on both cd and vinyl). You should check out their website. Here are a few of my favorite acoustic blues artists who've been recorded post 1960 (and thus have good sonics):
Black Ace
Rev. Gary Davis
Sonny Terry and Brownie McGhee
John Jackson
Fred McDowell
Bukka White
Skip James
John Hurt
Bill Broonzy
Snooks Eaglin
R.L. Burnside
Son House
Mance Lipscomb
Furry Lewis
Willie McTell (wasn't recorded post 60, but the lp, Atlanta 12 String, is great sounding music)
It might be worth taking a trip to your public library. They'll often have good compilation cd's of various styles of blues. It's a fun, cheap way to discover the tremendous range of styles that falls under the category "blues" and to find out what you like. Enjoy!