I've never had a problem with jury duty (of course my employer was paying me, which wasn't a factor, but it helped).
The only time I had to ask to be excused was when i was still in bed recovering from serious injuries. It was for Federal court, 100 miles from home, and the summons asked if there was any reason I couldn't serve. I wrote a letter and my doctor signed off on it and I was released. Have not been called since (had served twice before on fed duty).
First time I was called for local court I did try like hell to keep from getting on the jury when they were making selections. I knew the arresting officer (armed robbery case) and when asked if I knew anyone related to the case my hand went right up. Judge asked if that would keep me from being impartial. I couldn't lie, so I said no. Got stuck on the jury, but the guy pleaded out before the trial started the next day.