Good blood summoning spells?

[thejeff]

Yes.
It's pretty much what blood is about.

What you use in any given game depends on what cross-path mages you've got. For the troops, Devils and Demon Knights are particularly good, Storm Demons close behind. The main problem with the early spells is they only summon 1 at a time, so they're expensive in mage time. Ritual of 5 Gates is nice because it summons 5 different demons at a time.
If you've got astral the various Horror spells make good remote attacks or battlefield spells. Hordes from hell is a decent remote attack and you get a demon commander out of it. Nice if you don't have flying commanders to go with your flying demons.
Later on, Ice Devils make good SCs. All the uniques are worth summoning if you can get to them first. Some are better for diversity or battlefield support rather than SC duty.
Of course, if you're playing Mictlan, Lanka or Ashdod/Hinnom/Gath, you also get really nice national blood summons.