Without knowing what you plan to do with the notebook, it's hard to say.
If this is your first notebook and you plan on being mobile with it, go with a 14.1". This size offers the best balance, in my opinion (larger notebooks are difficult to transport since they are heavy and large, smaller notebooks generally sacrifice too much screen size and don't generally offer dedicated graphics options).
An HP Pavilion DV2500T is worth looking into. I would avoid Toshiba and Acer, since their build quality is generally poor. Asus, Lenovo (ThinkPads), and HP make nice systems. Dell build quality is usually poor, but their Vostro small business line offers slightly better build quality at more reasonable prices (but you will sacrifice looks).
Anyway, if you give us some ideas of what you might be doing with it, what your preferences are (on screen size style and finish, weight, gaming or not, etc...), we could probably make some better recommendations.