If you drop a normal brick on a hard floor the brick is likely to shatter. More models have special parts with narrow waist sections that easily snap. The c-shaped grips that hold poles either warp or snap and become useless.
More and more sets come with stickers rather than printing the pattern onto the bricks like they used to do. Stickers are really lame. They never go on right and peel off at the corners easily, but if you pull them off they'll definitely leave goop behind.
My kids and I still enjoy Lego despite this, but we haven't bought a new set for a long time.