Retirement calculators

Do any of you use a retirement planning software package that
you like a lot? I use the one on Fidelity. I like that I can build a spending
budget that varies over time, that it will do the medical cost estimation
for me and that it runs scenarios with different market condition assumptions.

I am looking to run the simulations on another program to see if the
results are anywhere close to the same. The assumptions seem to make
a big difference.