I do 4 days a year in BAs flight simulators. None of them are fun and they should be avoided at all costs.

However, if you really want to do this to yourself then decide what it is you want to get from your experience. If it is "playing pretend airline pilot whilst looking out of the window" then choose the A320 or 777 simulators, which have much better visuals and are just slightly more forgiving. If you want "testing my skill as an airman" then try to get a 747-400 simulator slot. No high res graphics and no mercy! You won't get a 744 anywhere near the runway for at least your first 5 attempts. After that you might get a controlled crash with a lot of assistance from the instructor but you'll get an excellent idea of how hard it is to fly one of these beasts. As a bonus you will earn considerable bragging rights that you have at least had a go at the queen of the skies and might just be able to crash in a helpful place if the both the pilots had the fish meal.