As far as the timeline goes, Simon's only been on two anti-Dracula crusades.

1986/09/26 - Demon Castle Dracula (FDS).................................Castlevania
1987/08/28 - Demon Castle Dracula II: The Accursed Seal (FDS)...Castlevania II: Simon's Quest

Thing is, though, his first adventure was remade a million times.

1986/10/30 - Demon Castle Dracula (MSX2)...............................Vampire Killer
1988/02/22 - Demon Castle Dracula (AC)...................................Haunted Castle
1991/10/31 - Demon Castle Dracula (SFC).................................Super Castlevania IV
1993/07/23 - Demon Castle Dracula (X68000)

The Sharp X68000 version was never released outside of Japan until it was rereleased on the PlayStation in 2001 with techno-remixed music, a Kojima art gallery, an Igarashi interview, some bad FMV, and new sprites for Simon and Dracula. It was called Castlevania Chronicle: Demon Castle Dracula, or just Castlevania Chronicles in the States.