which MST3K dvd set is best to buy?

[limeolives]

i am planning on buying Mystery Science Theater 3000 for my boyfriend for valentines day considering hes such a huge fan. i'm just not sure which dvd set i should buy. he loves the later stuff they did but im sure anything i buy him he will love.

anyway, which would you prefer to get if you had the choice? i just have no idea which season or edition to get! thanks!