I custom make my own, usually in Excel, for that specific character. I play few characters and usually do so for a long time, and I enjoy mucking around. Just exactly the information I need on the front, often landscape instead of portrait, and other information like equipment lists and other less-referred to information on the back. If a spellcaster the spells with cheat-sheet info goes either on the front (which will displace/shrink other stuff) or on a separate sheet. Occasionally if I have some tricksy spells I'll have the full text of the typed up on the back of the spells sheet so I don't need to refer to a reference book in play.
Oh, I also usually have a fold-out with my character portrait and name that I can put in front of me. Sometimes with some basic information for the DM in a large font size (AC, passive perception, etc.)
In 4e, where running someone else's paragon-level character if they didn't show was a pain because of all of the unique powers, I included a tactics section with common situations and powers to use to make it easy, especially pointing out fun combinations. For example, one character could use his Winged Dagger to change the source of a spell with some of my close burst spells.
I don't have anything against generic character sheets, and they often have a more pleasing aesthetic, but I go for ruthless practicality first. I don't look at a sheet for the vast majority of a session. If I'm looking at it that means I need a specific piece of information and I want it both handy and with enough detail I don't need to access a book. I've even had the text of some conditions I inflicted just so I had them ready if the DM asked.
EDIT: Here's a sheet I had for a 4e character. But it was a Word document and this machine has Libre Office installed and all of the formatting is bad. It would be one color-coded front page with all powered, skills, defenses, HPs and special modifiers, and then a wordy page back with tactics. But when I just opening it it wasn't nicely formatted (text boxes moved, spilled over onto second page, etc.) so I hope you get the idea.
View attachment Silith cheatsheet 10.docx