BMO3---For versatility (more bang for your buck), I recommend getting one of the longer ones. Have Mercy, the original, is 2 hrs and has a good mix of tempo, hill work, sprints, etc. It's my favorite longer Spinerval. Have Mercy the Sequel (also 2 hrs) is more endurance focused, as the individual sets are longer. Tough Love is 3 hours and the new DVD is 5.5 hours. The beauty of the longer workouts is that you can break them down into shorter workouts.
If you want a short workout, Hillacious is my favorite for the fun but very difficult factor. It's just over an hour and will help with your climbing.