For bedtime, I shoot for 100 mg/dl. That seems to be the bedtime number that will allow me to hit my morning fasting target of 70 - 80 mg/dl. Those are the numbers I think of as being attainable and within a generally accepted normal BG range. If I hit those specific targets 25% of the time, I'm happy.
I'm 80-120 for bedtime and between 60 and 99 for fasting, in general, around 80% of the time.
Between meals, anything between 70 and 119 is acceptable. I'll hit that range 80% of the time. Anything above 120 at any time will be corrected for with insulin. for my out of range numbers, 12% are hypos that need correction, 6% are highs below 180, and 2% are highs above 180.
That's about as good as it's going to get for me and I try hard not to freak out when I'm outside of my range, but I'll still get occasional way out of range highs, or go on a vey bad BG streak lasting days, that turn me into a self-doubting, sobbing mess.