I give every opportunity for several reasons.
I'm a carrier for Hemochromatosis (high iron in blood) and doc feels it keeps the levels down some. I'm also O-Neg, so my blood is sought after.
I will say I gave up on the Red Cross. They used to come to my rural city every eight weeks put on by the local VFW. I would go in, donate, and then schedule the next appointment when they were back, and try to be in the first group. The experience the last several trips wasn't up to par (timeliness is very important to me and they were 2 hours behind leaving their main office last time), so i switched to the regional community blood bank.
Blood stays local-ish, office is 20 minute drive away and I do other errands that day, and appointments are plentiful and always right on time.
Now, if we could only convince the IRS that donating is tax deductible...