Ohh, I am all over the place with names so I will give you the names of some of my sims and the thought process behind each.
Agaetis Byrjun: Icelandic for 'a good beginning'. Originally the name for a founder sim I had in a Sims 2 legacy I started maybe a year before Sims 3 came out. When I got Sims 3, I recreated him to begin my whole Sims 3 experience. Sometimes I will search foreign language meanings that embody the sim.
Reuben Steele : This is the first and middle name of an ancestor of mine I recreated for my game. Other family names I have used for my sims include Antoine Desrosiers and Alexandre Desrosiers.
Sometimes I use names carried forward from other Sims games. When I began playing TSO my first character I named Jessa Dakkar. So when I registered for the Sims 3 site I changed my user name to that to honor her, and she is recreated in my game. A few years into TSO I acquired a second, founder account, and the sim on that one was already named Avalanche Wolf. I have recreated him in my game as the mayor. In Sims 1 when Superstar came out I made a sim I named Joie Starling as it sounded like a half decent starlet name. I have her recreated in my current save too, that name has been dragged from Sims 1 to TSO to Sims 2 and now Sims 3.
Some of my characters are recreations of Sims from other games that were made by EA, like Brandi Broke and her children and the Grunts. I have a sim who is a carryover from my Sims 2 game and the son of Nervous Subject. His name is Malien, and appropriately in Sims 3 he got abducted and had a little alien girl I named Aurora. Aurora because it sounds rather celestial. Malien is a scientist and created a plant baby, her name is Acacia Willow, because plants.
Fubar Dilligaf : I did give TS4 a good try and my last attempt at really finding my place in the game and some fun with it was a sim I created I named Fubar Dilligaf. Because that is what is was and how I felt. The name is an acronym. I always meant to give him a dog named Snafu but haven't got there. Fubar is very happy to be living in my Sims 3 game these days and I am happy to have him there.
Some names are picked at random using the game's system for that. Others come from who even knows where. Some names were placeholder names that I meant to get around to changing but haven't.
I have one sim named Clemens Rehbein because I was huge into Milky Chance at the time. It's fun to see him around town playing guitar and singing for tips.