You play 6 max right OP? A standard Tag at 6 max is something like 20/15. 20 VPIP / 15 PFR. The tighter players have lower VPIPs/PFRs, obviously. You will occasionally see somebody is like 22/3, which means they're tight and limp or cold call raises the majority of the time. So when they raise (or reraise) it's almost always a huge hand. The nittiest players I've seen are somewhere around 14/10. I personally am about 23/17, which is TAG but pretty aggro preflop. I raise and reraise a fair bit.

The fishy players will have really odd lopsided stats like 40/2 or 70/30. Most people with vpips over 35-40 are bad postflop players and bad players altogether generally. Most good players have a vpip of 15-30, PFR 12-20. You want to have your PFR be very close to your VPIP, which just means that you are raising often preflop when you play and are more apt to reraise somebody than to just call preflop.

So look to play against players with high VPIPs, and players with low PFR stats are also easy players to exploit and not difficult at all to play against.