As of right now:
Phantasy Star
Kingdom Hearts
Pokemon GS
Any Tales game
Scribblenauts
Megaman Starforce 3
Ragnarok Online
osht--
Golden Sun DS, definitely
Miles Edgeworth
Cop: The Recriut
Might be the DSi.
As for SavSender, make sure you have all your settings right [ip, ports, etc.] and have all the necessary tools.
It didn't work for me either... until I double-checked my ports. lol
From personal experience, I wouldn't recommend Fireworks for sigs.
I'd probably stick with the free GIMP, which is like a free Photoshop.
For fonts, I usually use dafont.com