Here is the complete series with all crossovers and extras.

Volume 1
Underworld Unleashed 1
Aquaman 14
Azrael 10
Damage 18
Deathstroke 53
Green Arrow 102
Guy Gardner: Warrior 36
Manhunter 12
Extreme Justice 10
Flash 107
Primal Force 13
Spectre 35
Underworld Unleashed: Apokolips – Dark Uprising 1
Green Lantern 68
Hawkman 26
Justice League America 105
R.E.B.E.L.S. ’95 13
Starman 13
Detective Comics 691
Fate 13
Impulse 8
Ray 18
Steel 21

Volume 2
Underworld Unleashed 2
Catwoman 27
Damage 19
Green Arrow 103
Guy Gardner: Warrior 37
Lobo 22
New Gods 2
Robin 23
Underworld Unleashed: Batman – Devil’s Asylum 1
Batman 525
Extreme Justice 11
Legion of Super-Heroes 75
Primal Force 14
Spectre 36
Showcase ’95 12
Superboy 22
Underworld Unleashed: Abyss – Hell’s Sentinel 1
Green Lantern 069
Hawkman 27
Justice League America 106
Underworld Unleashed: Patterns of Fear 1
R.E.B.E.L.S. ’95 14
Adventures of Superman 530
Detective Comics 692
Justice League Task Force 30
Underworld Unleashed 03
Legionnaires 32
Ray 19
Fate 14
Superman: The Man of Tomorrow 3
Robin 24
Aquaman 18
Starman 71