I used a VeeBee one for DD. It has mesh sides, so she couldn't even stick her arm through, or lose toys easily. It comes as 3 pieces, each with 2 panels - use 2 pieces to make a square, or 3 pieces to make a hexagon. It was fantastic! As the hexagon shape, there is enough length between opposite points for me to be able to completely lie down (I'm about 165cm tall).

And it is also big enough to be able to put the Christmas tree in it to keep little hands away from the decorations!