Cock brand curry pastes come highly recommended!
Curry paste is a moist blend of ground or pounded herbs and/or spices and other seasonings. Curry paste is primarily known an important ingredient in Thai cuisine, and it can also be a generic commercial product which substitutes curry powders or spice blends used in other cuisines.
Buy the smallest container you can unless you make curries extremely regularly as many curry pastes, including the one shown, are water based, so once opened, have a fairly limited fridge life.
Freezing curry paste
Divide the curry paste into usable portions and freeze them separately in disposable plastic coffee cups for later use.
Update: I have since discovered that because they do not freeze solid, the curry pastes pictured are best kept by cutting an opening in the plastic bag inside the container and simply freezing the pot. The paste can be spooned out directly from the freezer!
Red Curry paste
Green Curry paste
The ingredients for Green curry paste is similar to red curry paste, except green chilies are often used in place of the red ones.
Yellow Curry paste
Buy the 400g pot and freeze immediately, see above tip. These water-based pastes will not keep in the fridge once opened. They will go mouldy after a few weeks.