[DnD 3.5] Best Spells of Any Class?

[Icewraith]

If you want to get sneak attack back I believe Nightstalker's Transformation (Sor/Wiz 5) would work. Just use it after you're out of the other fun spells.

Also ennervation (4), Draconic Polymorph (5, assuming your dm hasn't houseruled/banned Polymorph), and Animate Dead (3?). What you really need at that point is a spell named "Call (not summon) Learnean Pyrohydra," but I think you'll have to research it or hunt the buggers the old-fashined way.

Also: solid fog/freezing fog
Glitterdust (2) and nerveskitter (1) for low level spells.

Edit: Regarding streamers, stremer destructibility is why it's best to target one target with multiple streamers, preferably one with low melee damage and without iterative attacks (i.e. arcane spellcaster).