Wanting options for the least expensive loan of $50K for 1 year.  I
have equity in my home if that's the best answer.  My current lender
is offering 3.99 apr for 6 months.  I was hoping to do much better
than that.  Or what about a cash advance from one credit card and
"immediately" transferring the balance to a zero percent balance
transfer card?  I've looked at various cards, but they're tricky
regarding cash advances, and some are tricky regarding receiving
balance transfers.  What can you find out there?  Thanks very much.

Beating 3.99% will be very difficult.  There are 0% credit cards out
there, but to get $50,000 at 0% is way beyond anything I've seen.  My
credit rating is quite exceptional and I know I can't get that good of
a deal, especially with a cash advance.

That lender who offered 3.99% for 6 months would likely be willing to
give you 4.49% for 1 year if that better suits you, just ask him what
you could get a 1 year loan for and he should make an offer.
Assuming you make no payments on the loan and simply pay it all back
after the 6 months or 1 year, this is the interest you'll owe:
6 months at 3.99%: about $1,000
1 year at 4.49%:   about $2,250

It sounds like you have a great credit rating to get 3.99% out of the
equity.  Mind if I ask what the money is for?  I'm only curious
because it's an unusual loan that you are seeking out yet you seem to
know exactly what you want.