If you want power then Dewalt but there a bit numb but they take alot of abuse, if you want precise and good quality then bosch or panasonic, bosch batterys are not that great and there expensive to replace, makita is a cheap alt to dewalt
ryobi are ok but not really designed for heavy use, all the above are a world away from your old drill, my dewalt drill will snap my arm off if dont pay attention and will snap a 10mm drill bit without thinking about it
if you look around you can get reconditioned tools alot cheaper, you get new batterys and the tools are brand new possibly a few scratches but thats it!
if your going to use it a bit then 30min charger is a good addition.
14.4v is great for weight and my tools are as powerfull as 18v that everyone else uses but mine are alot lighter! 2ah is a minimun nimh is better than nicad, i have had 3 years out of the dewalt 2.6ah batterys and there just starting to go but they have been abused.
have a look round this place, I buy all my tools from here and they have been great,
http://www.marshallandparsons.co.uk/
if you need any more just ask.....