Repository of classic sci-fi?

[Dan55]

Could the series be the Flandry series by Poul Anderson?

[No Such Agency]

Oh, and what I recall about the series I missed was that it involved some sort of interplanetary agent, secret agent, or maybe a mercenary type, one book featured space pirates, and there was the usual bevy of space mistresses/space sorceresses. I think the series was at least three books and less than ten (so not one of those massive, long-running series, but one that at least had several books in it). I may be misremembering some or all of those details.

Probably not what you're thinking of, but the "Retief" books by Keith Laumer were great, at least when I was younger.  Lots of fun, bizarre aliens, space babes, silly swashbuckling plots and un-subtle political allegory.  Also TONS of sexism both overt and assumed, but they reflect the time when they were written. 

(Noted SF writer Theodore sturgeon was less charitable, even at the time: [Sturgeon] rather caustically dismissed the series in 1971, saying "I find nothing admirable or amusing about lies and double-dealing... What slams the ultimate lid on the whole scam is Laumer/Retief's light-hearted callousness toward one species or another of funny little green ni**ers." - Wikipedia)