Greater gods would easily beat any god of intermediate status or lower. Intermediate deities would in turn easily beat any god of lesser status or lower. Lesser gods would easily beat a demi-god.
Greater: Akadi, Amauntor (became Lesser after the fall of Netheril and before his death), Bane, Chauntea, Cyric, Grumbar, Istishia, Kelemvor, Kossuth, Lathander, Myrkul, Mystra, Oghma, Shar, Silvanus, Sune, Talos, Tempus, Tyr.
Intermediate: Beshaba, Bhaal, Gond, Helm, Ilmater, Mielliki, Selune, Tymora, Umberlee.
Lesser: Auril, Azuth, Deneir, Eldath, Ibrandul, Iyactu Xvim, Leira, Lliira, Loviator, Malar, Mask (formerly intermediate and briefly demi), Milil, Moander (became demi for a time before his death), Shaundakul (formerly demi), Talona, Torm, Waukeen.
Demi: Finder Wyvernspur, Garagos, Gargauth, Gwaeron Windstrom, Hoar (formerly lesser), Jergal (formerly greater), Karsus, Lurue, Nobanion, Red Knight, Savras (formerly lesser), Sharess, Shialla, Siamorphe, Ulutiu, Uthgar, Valkur.
Of the greater deities, if we're just talking a straight fight, then one way to rank them is by the character levels of their avatars:
Bane = 111*
Shar = 110
Myrkul = 91
The Elemental gods (Akadi, Grumbar, Istishia, Kossuth) = 90
Silvanus = 85
Cyric = 84**
Oghma = 83
Mystra = 80
Talos = 79
Kelemvor = 76
Amauntor = 73
Sune = 65
Tyr = 63
Lathander = 61
Tempus = 60
Chauntea = 60
* note that this is before his death. Comparing his post-resurrection levels would involve converting 3E->2E, which I can't be bothered to do right now
)
** he would presumably have had more than this while he still had the portfolios of
the dead and
death, but there are no official stats for that.