A gate at the top of the stairs needs to be very secure yet easy to operate. It is also essential that it be a hardware mounted gate and not a pressure gate. Finally, the gate should not have a threshold which could cause you to trip.
Of the gates that meet the above criteria, for several years my favorite has been the Evenflo – Secure Solutions Swing Gate (Model 1050). This wooden gate is sturdy and parent friendly. It hinges open the full width of the stairs (28 to 42 inches) and can be readily removed whenever desired.
Installation is very easy except when tall baseboards or fancy banister posts are present. These challenges are overcome with the use of some additional pieces of wood (i.e. 1" x 2" x 36" poplar). Additionally, you can avoid drilling into a finished banister post by using cable ties to secure the poplar to the post.
Unfortunately, there is a caveat to this recommendation. Evenflo has recently moved its manufacturing out of the U.S. and the quality and consistency of the gates has diminished. Carefully check your gate for smooth operation. If the gate does not slide freely, exchange it for another one. When manufactured properly, this is still the best gate going and one of the lower priced ones as well.
Other viable options for the top of the stairs include the KidCo – Safeway (Model G20), The First Years – Simple & Secure Stair Gate (Model 3620), Cardinal – Stairway Special (Model SS30A) and Lascal – KiddyGuard (Model 5-12320). New and sometimes improved gates are being continually introduced, so "stayed tuned" as we review the new offerings, we may find even better options in the near future.
Before you purchase a gate for the top of the stairs, check to see whether the gate can be placed across the hallway and perhaps moved up the hallway while still preventing access to the stairs. Depending upon the configuration of your home, you may be able to move the gate away from the top of the stairs, making it easier to install and operate. In doing so, it may even prevent access to an "off-limits" room or a balcony.
Also, don’t forget to prevent access to the bottom of the stairs, as crawling babies can climb the stairs only to fall back down.