Last year Bye Bye Robot released six posters by Matt Ferguson, one for each of the TOS movies. Now they are continuing the series with four TNG designs. Each poster is 12x24 inches, and you can pick out your individual favourites, or get a set of all four. I think the Insurrection design is especially stunning:
Bye Bye Robot have also recently released a new TOS print. This art nouveau portrait of the 1701-A is by Alicia Andrew and is available as 13x24 inch print.