I would say either a makita bhp451 or a hilti sf180-a but on drill dealers we like to
give you the good and the bad,

makita bhp451 good : long lasting batteries, handy led light, 24mm metal chuck
bad : when bateries die they are very expensive, motor and brushes are weak and will give up the ghost on heavy use

hilti sf180-a good : extremly powerfull drill, very durable will take any abuse
bad : very very very expensive to buy ..........

well thats my opinion hope this helps