I do not think what brand of spice you use really matters. What is far more important is to:-
Always check the sell by date on the packaging - I have seen up to two years difference on the same shelf. Do not be tempted to buy the package that is twenty pence cheaper then the rest - guaranteed to be old stock rather then just a mistake!
Always use whole spices and grind them yourself when required if possible - whole spices have a much longer shelf life then ground and will be stronger in flavor once freshly ground - Seeds of Cumin, Coriander, Cardamom, Fennel and Fenugreek also grind whole Cinnamon sticks, Nutmegs and Cloves. Most important always use freshly ground Garam Masala and try and use all other spice mixes freshly ground yourself as much as possible. Also substitute fresh Chilies for ground and don't be shy of using fresh coriander as much as possible.
Finally, Only buy in the right quantity of spice that you know that you will utilize before the recommended sell by date otherwise you will only be throwing it away when it is dried up and tasteless.
Bon spice