Not sure if this has been post yet, but...
Yes, I mean how did you name the red-haired guy?
Since he was such an annoying brat, I named him after one of my least favourite Hollywood celebrities (don't ask me who).
What about you?

I played so many files, but I remember always naming him various cuss words.

I started naming him Team rocket names (James .Jessie, etc). I also remember naming him with random names from the anime (Gary, etc.)

The first time I played I actually thought his name was ??? so that's what I named him. Then I named him various potty words, because I was about eight years old and that's what eight-year-olds do, ja?

Same here. Then I started naming him people that used to be my friends, and his latest name is now d0-(=3 (For Sex Offenders lol)

I was 7 when I first played Crystal. And I named 'Loser.' Yes. I did. How childish. Now that I am older, I would name him something like 'Omega' (based on a friend's character I dislike.)

You mean the guy from Sonic?

No. I had a friend who made an original character called Omega (I have some original characters too.) My friend made his character 'better' in mine in every way. I hated that. But thinking about it, I might name the rival after this old friend.

Well, he TOLD me his name was ???, so how was I supposed to know otherwise...?

Well like many others I thought he was actually ??? on my first file. On the next file for some unknown reason i decided to call him Catty. That was ages ago.
On my current Crystal game I have called him Dave(because my player character was a young girl called Bob)
Bob and Dave are names that work together for some reason.

I gave him a simple 3 letter name to correspond with the '???.' I named him Max, short for Maxence, which is fitting since it's meaning is 'greatest'. I like the name maxence for him, it seems sophisticated enough for Giovanni's supposed son.

I named him Shadow most of the time (since I called myself Darius, and both were characters of mine who were also brothers and rivals).

Symbolism is cool. Before though I did name him after a bully I knew as a kid heh. Was satisfying to beat him over and over again.

I call my rival(s) by the name of my least favorite people. I named the red headed dude 'Mika'.

I always name my rival Ethan (my name is Ian and for some reason I like the fact that both names sound nearly identical). I also remember calling him Ivan before, and since I was like, 6 years old when the game came out, I probably named him ??? a couple of times, too.

I seem to remember having a laugh with my friend one time by naming him "Nobody". To me, that was what my rival was...

It was the funniest thing when the policeman said, "So Nobody showed up here, is that right?"

I was happy after seeing that (or something like it, I don't remember...)!

AEPMT

well, at the time I was young, so when I first battled him, It said his name was ??? so i thought he had a name, you just didn't figure it out yet. when you get to the lab, Elm asks you what his name was, so i said: ???. Then like the next year, I figured out you're supposed to name him. But, another problem rose, I didn't know if he was a HE or A SHE. So I had to think of a name that can go for both. now i usually call him Caleb (The name of one of my friends).

The first time I played, I actually believed his name was "???" so when the guard asked his name that was my response. I think I was even afraid that if I "lied" something bad would happen. As I got older and "matured," I went with various forms of profanity, most notably the ones beginning with "Jack" and "Dumb" and ending in the same three letter word.

One file I named Buttler and another time i named him after my friend Roy.

I named My rival Eragon no idea why???

Well, first time it was ??? cause I thought that was his real name and I wanted to be honest with the police man, but then in later replays I named him various friends names, not sure why though.

I don't it it. To me it was odveus that you had to name the red headed kid. His name was not '???'.My favorite and current name is Ash. I don't know why.

lol, i always named him jason cuz that was my best friends name.

I always name my opponent Connor, after my mate who taught me loads about the Pokemon games.

I called my GSC rival Zack... He was a guy I didn't like too much in Junior High, so I had a field day kicking his butt to the curve.