Caulking is a trade in itself.  The importance of  sound caulking cannot be overstated.  On the exterior, most wood rot occurs at failed caulking joints. On the interior, much time can be lost removing and replacing broken caulking.  Cracked caulking must first removed in order for it not to crack again.  It can then be replaced with top line, industry standard caulk DAP 230.  We also use polyurethane caulk, such as NP1, on expansion joints where, for example, wood meets brick. 
Cracks in driveways need to be caulked so the edges of the cracks do not break off and form holes.  After pressure washing the surface, we use a two part, polyurea self-leveling masonry caulking.