Yea Complete Adventurer really has some nice additions to the Assassin spell list. Of those spells I'd recommend picking up
distract assailant and
sniper's shot. Though I'd check with your DM to make sure you can use these as they seem a bit overpowered compared to the other assasin spells. Since
distract assailant makes your opponent flat-footed until their next turn, allowing you (not to mention anyone else) to make a full-attack worth of sneak attacks on the creature, and
sniper's shot allows you to make a ranged sneak attack at any range. Both are pretty powerful additions to an assassin's arsenal if allowed.
After that I'd definately go with
featherfall and
truestrike, the first being useful for those plummets to escape or to catch yourself and
truestrike negates miss chances - allowing an assassin to hide in shadows and then sneak attack a target also in the shadowy area when normally the miss chance for being in shadows would negate the ability to sneak attack. Though the
jump spell at the higher caster levels absolutely rocks, having a +30 to your jump checks combined with some
featherfall action makes for some serious crouching tiger hidden dragon moments!
Edit- For a wee fix on the
distract assailant spell to make it useable for balanced game-play just have your DM alter the spell so it "makes the target flat-footed only against the caster and for a single attack, at which point the target is no longer considered flat-footed." Not one of the more well thought out 1st level swift spells I must say lol.
