Well, this is fun topic. Lots of room for imagination...Let's see here:
1) Say this guy is supposed to be a suave, tuxedo/dinner-jacket wearing spy:
If we're talking the 1960s/1970s--then a .38 Colt might do him. Or a Colt .32 auto.
If we're looking at the 1980s/1990s, then we have to go a bit heavier and get into automatic territory. Maybe one of S&Ws compact automatics. 6906 series. H&K P7M13, Walther P5 compact.
If we're looking at 2000s, then maybe an H&K USP compact or Walther P99.
2) If we're talking about a more "government operative" type spy from Tom Clancy or Carsten Stroud:
1960s/1970s--Colt Commander .45 or a Browning 9mm
1980s/1990s--S&W 5900 series 9mm or a Glock
2000s--Sig 229 in .357SIG
That's just off the top of my head.
CDS
Simma=Sig P229 9mm
Winona=S&W 4006
Domino=Walther P99 .40