Most of my favourite early Giants were sculpted in the seventies (or early eighties) by Tom Meier for Ral Partha, this is a partial selection. Most were from the period when Citadel were producing them under license in the UK, and are part of the Ral Partha ES/01 "Personalities and Things that go Bump in the Night" range.
The raised club version of the 01-121 Hill Giant does not appear in any Ral Partha catalog but is shown in the RP section of Citadel's Compendium One, as the lowered club one appeared in the 1984 RP catalog, it may not have been around for long. The 01-118 Werebear in Manform is shown as a Giant in Compendium One. See also the section on the 01-099 Armoured Giant riding on War Elephant variants.
The Minifigs Mythical Earth guy is here because he doesn't fit anywhere else (yet!)
Early Giants: Tom Meier & More
01-313 Troll (Forest) Giant, 01-121 Hill (Forest) Giant, 01-313 Troll (Stone) Giant, 01-121 Hill Giant, 01-109 Cloud Giant, 01-118 Werebear in Manform, 01-052 Hill Giant (v2), 01-067 Hecatron, 31-028 Armoured Cloud Giant, Minifigs ME39 Giant, 01-052 Hill Giant (v3), 01-057 Frost Giant, 01-059 Fire Giant, 01-052 Hill Giant (v1)
01-052 Hill Giant (v1)
01-052 Hill Giant (v2)
01-052 Hill Giant (v3)
01-057 Frost Giant
01-057 Frost Giant
01-059 Fire Giant
01-067 Hecatron
01-090 Storm Giant
01-109 Cloud Giant
01-109 Cloud Giant
01-118b Werebear in Manform
01-121 Hill Giant (Forest Giant)
01-121 Hill Giant
01-313 Troll Giant A (Forest Giant)
01-313 Troll Giant B (Stone Giant)
31-028 Armoured Cloud Giant
Oracle & Asgard Giants
Asgard FM19 Storm Giant
Asgard FM39 Large Armoured Storm Giant
Minifigs ME39 Giant
Oracle Miniatures: OR10 Giant hurling Rock
Oracle Miniatures: OR5 Stone Giant
Pendragon PD44 Cornish Giant