There was a much more recent, bigger one in Alaska: https://en.wikipedia.org/wiki/1958_Lituya_Bay_megatsunami

Why do you consider the Lituya Bay megatsunami to be bigger?

The prehistoric megatsunami was estimated to have a "minimum tsunami wave height of 170 m at the shoreline." The Lituya Bay crest was estimated at 90 m.

The run-up at Lituya Bay might be higher but, to quote from this Science paper, "run-up is a complex process governed by local bathymetry and topography".

If I was sitting in Lituya Bay, I'd probably be more concerned about how high I had to be to avoid the wave. To quote myself: "Shoreline height is a complex process governed by local bathymetry and topography"

One potential source of a mega-tsunami in the future is Cumbre Vieja, a volcano in the Canary Islands that has an unstable side. [0]

This "fact" is actually in dispute and is somewhat controversial.

[0] https://en.wikipedia.org/wiki/Cumbre_Vieja#Future_threats

This is the one that would theoretically hit the US eastern seaboard like a wall of water right?

According to the text on the other end of that hyperlink, yes.