I'd agree with this. Gradius 1 needs real boss fights (understandable given 1985, but if we're going to compare than we're going to compare). Salamander has some neat stuff in it, some of which remains unique to it such as vertical levels. Gradius 2 is an excellent continuation of the two and really pulls it all together, with a good mix of new and old.Gradius 2 > Salamander > Gradius 1
Gradius II. Currently digging the difficulty curve in the Famicom version. Hope to pony up the cash for the PCE port in the future.
NIPPLE LAZER
I'm probably also in the minority by saying I like Gradius III, despite its legendary difficulty.