On the others - wipers seem to make the problems worse - just open the sliding window on the side, accept some water through the window - it will leak out through the doorseals anyway and do some sideslipping i.e. for landing and so on.
Assuming there is a sliding window, of course! Some types ( A109, for example), have only a fixed window panel.
The military Puma was bad, when parked in rain it used to collect a pint of cold water in the window frame which would dump down your right leg and into your boot when you lifted to the hover. The radios and intercom used to fail completely, usually in IMC, due to water ingress into the nose avionics bay, hence the use of "black bodge tape" over the panel edges in an attempt to seal it. In the days before the polyvalent intake filters were fitted, when it came unstuck (usually in rain!) it was likely to go up the nose and into the open engine intakes. Seeing a recent example made me smile - even after the "modded panel seal Mk2" it's obviously still a problem as this one still sported the characteristic old-fashioned black square of tape on the nose panel!
Every S-76 I've flown leaked water onto the pilots from above - most pilots use laminated charts over their legs as aprons when it rains!