Now if your father is an experienced flyer you are delving into some pretty personal area. Since everyone has different tastes. You could easily select a plane your father hates. Not that he would ever tell you that. The best thing you could do for him is to go to you local hobby shop,
www.towerhobbies.com or
www.horizonhobby.com and pick up a gift certificate for him. In some cases picking a plane for him would be like him picking your night clothes for your honeymoon.
If he has never flown or only dabbled with electric flight then RCKens sudjestion of the Tower Trainer (available at
www.towerhobbies.com ) can not be beat for perfomance and cost.