Traditional Wood joinery is seldom used these days, given up for quicker methods such as screwing and nailing.
Many Traditional Wood joints are still used today in high end items and cabinetry. Joinery is somewhat a lost art, however traditional wood joints can be much stronger and durable than their easier counterparts.
Any of these joints (esp used without nails, screws, staples, brads...) should be properly glued. If glued properly many of these can be stronger than joints with nails, screws, etc..
Simple (These are the basis of screwing and nailing still):
Splice (aka Scab Battened, or Battened Butt)
Rabbet & Dado
Inverted Rabbet & Dado
Wood Spline Miter
Closed Mortise & Tenon
Mortise & Tenon with Haunch
Full Through Dovetail
For Boards & Flooring Type applications:
Off-set Tongue & Groove
Tongue & Groove
(Should these just link to appropriate wiki articles or all have images?...If anyone would like, feel free to add images, etc...)