Got Ikaruga for the GC way back, Gradius V as a gift two years ago but I haven't heard of "Under Defeat" or "Border Down"; I'll have to check them out . Also I do see what you mean Coop and I do agree that those games are quite refreshing. However as you just said, they only ever come around once in awhile.
I do miss the classic side scroller games like R-type and the Gradius series. Sadly I think the one I have barely touched is the Raiden series but that's only due to availability than me actually getting into it.
Heck I even tried out Söldner-X: Himmelsstürmer and enjoyed it despite how much it's an "acquired" taste in terms of shmups. Just that they simply aren't as popular except as a niche genre
I'm with ya Coop on greater/fresher things to come out, however until something does. I simply enjoy whatever comes out that avoids one of my own personal pet peeves, which are titles that provide little challenge or do so purposely.
Unless of course it's a parody or joke game
Also perhaps I should note this, if I can play Quest 64 (THATS RIGHT QUEST 64) 3 or 4 times all the way from the beginning to the end and some how some way find something I liked about it... Maybe I'm in some way far left side of the gaming spectrum that is difficult to turn off.