I have the Spell Compendium, it always makes the rounds whenever a Sorcerer gains a new level, or clerics are memorizing spells. Many of the spells are fine, but I have also run into a few "WTF...um no pick something else" spells. The Player's Handbook has the basic assortment of spells that will be useful. A phrase I have coined (after one too many search through the Spell Compendium to look up a spell) is "Master these spells first." (said while patting the Player's Handbook)
It is easy for me to sub out a core book spell for something else if I get bored with Fireballs and Magic Missles, but the fact is those spells do the job and do it well. It is wonderful to have the players say "What the hell is that spell?", but it is also awful to be looking at a spell on a NPCs list in an adventure and say to yourself "What the hell is that spell?"
When I started playing, there were a very small selection of spells per level that were available, the 1st ed. Player's Handbook contained, what seemed at the time, a HUGE expanded list of new spells to cast, but Light, Detect Magic, Cure Light Wounds and Magic Missle still do the trick.
No expansion of the spells are necessary, if you want something new try using the spell in a new way. While they may be cool, there really is very little need for spells beyond the Player's Handbook.
