I looked through a few of the highly rated ones, but I'm having a hard time finding one that is right for my needs. :-\
I really liked the appearance of the one pictured at the top of thread, and it had this uncanny ability to prevent my pdf reader from crashing, even while putting a heavy load on it (whatever was done to give it that magical power is a load of win all by itself). However, the automation, while one of the better ones, was really just getting in the way more than helping me. It felt like the sheet was taking up too much RAM. With a more modern system, it may have been a lot smoother. But really, I'm not a big fan of automation in character sheets. If there were a version of it that were unobtrusively form-fillable, that would have really been a great possibility for me.
Some of the other ones I looked at seemed okay, but none of the other ones really were any more appealing to me than the official sheets that I'm currently using--which is kind of sad because I was really looking for something a bit more visually evocative than the official sheets.
One problem that I have is that many sheets seem to give the "wrong" amount of space to various parts of the sheet. For instance, I want a very large amount of space for the race/class abilities section, because I'm not just going to write "Cunning Action", I'm going to write "Cunning Action: Here are all the rules for what it actually does".
On the other hand, I don't need 10 entries for weapons, or space to record NPC's birthdays or whatever.
So, I find myself still searching for the right sheet for me.