http://www.punkrockblues.co.uk generally guide me in this department. Have seen some great bands that they’ve put on. Bands that are more bluesy that I’d particularly recommend are:
Scott H Biram, does some really heavy stuff, as well as mellower stuff like this:
Guadalupe Plata (slide guitar stuff from Andalusia):
James Leg (throat shredding dirty blues. Used to be singer in Black Diamond Heavies who are also well worth checking out):
Bob Log III (nuts slide guitar played by man with motorcycle helmet with a phone receiver planted in it):
Fat Possum record label also a good source of modern blues. RL Burnside (old blues) did an album with Jon Spencer, it’s great. I absolutely love this song: