Scamp of The Cart Driver somewhat recently wrote Anime Archetypes: The Superior Appeal of the Tsundere for MAL (via), in which he said:

There are some debates over who the original tsundere is. I've seen it argued that Lum from Urusei Yatsura was, but she's very open about her affection so I don't think it counts. However there's no doubt which character became the popular face for the term with anime fans. That would be the hot-headed robot pilot, Asuka Langley from Neon Genesis Evangelion.

While I don't doubt Asuka's current status as the popular and archetypal 'first tsundere' in anime fandom today, I find this status interesting. Particularly, it leads me to reflect on the transient nature of something being a famous or well-known anime. Because, you see, Asuka is not the first famous tsundere that Western fans were exposed to, not even the first one in a big series. Who I'm thinking of here is Akane, from Ranma 1/2.

Akane's a clear and undeniable fit for the classical tsundere; she's hotheaded and quick to mete out some violence to the object of her affections (that would be Ranma), periodically soft and affectionate, and of course neither she nor Ranma are at all willing to admit their love for each other. Ranma 1/2 itself predates NGE by several years and back in the 90s it had a massive presence in anime fandom. Despite all of that, today Ranma 1/2 and memories of Akane have faded from fandom, including her archetypal tsundere nature (to the point where Scamp didn't even bother to mention her). Instead she's apparently been displaced by Asuka, who may not even be a tsundere as such, as well as later characters that she seems pretty clearly a template for, such as Love Hina's Naru Narusegawa.

(You can argue a lot about if Asuka actually ever likes Shinji. As for Naru, Scamp's description of her behavior in his article applies just as much to Akane.)

I can speculate about various reasons why Asuka has stuck in people's memories and Akane hasn't, but it's more interesting for me to just note that it's happened. An entire influential series and its characters, one that inspired or at least touched a whole generation of fans, has just disappeared from the modern landscape of fandom. If you'd told someone in the mid-90s that Ranma 1/2 would be barely remembered or mentioned in fandom in twenty years, I'm not sure they'd have believed you. Yet here we are.

(In the early and mid 90s, even if you didn't particularly like Ranma 1/2 you could hardly avoid hearing about it if you were part of anime fandom. People cosplayed, people talked about it, people wrote a huge number of fanfics (some of them well known and relatively influential), and so on. You could say that it was kind of the Naruto of its day.)

Sidebar: Some views on why this happened

I suspect that a fair part of it is a combination of fandom turnover (and growth) and the relative views of both shows. I wouldn't be surprised if most old fans from the 90s who've been exposed to Ranma 1/2 and Akane have left (modern) anime fandom, and certainly fandom has grown a lot since then. At the same time, new fans are much more likely to be told they really should watch Neon Genesis Evangelion (which is considered a classic for good reason) than that they should explore Ranma 1/2 (which is, uh, not as good as NGE and is much bigger and more sprawling), so they're much more likely to either see or hear about Asuka than Akane.

(Leaving fandom is not the same thing as not watching anime any more, and for that matter fandom has fragmented. I know of at least one cluster of relative oldbies that barely crosses over into the modern anitwitter or MAL or ANN based fandom. Scamp was of course writing his article for the MAL fandom audience, since that's where it was published; your mileage may vary elsewhere.)