Yes they can.
Be very careful with those Fireballs as there is no built-in way of excluding anything or anyone from the area of effect.
If you want to insist on centring Fireballs on yourself but you'd rather not be extra-crispy then check out the feat Selective Spell from Shining South.
Prerequisite Any other Metamagic Feat
Benefit You can modify an area spell so that it does not affect one designated creature within it's area. All other creatures in the
spell's area are affected normally. Selective spell has no effect on
target or effect spells. A Selective spell uses a slot one level
higher than the spells normal level.
Or Sculpt Spell from Complete Arcane.
Prerequisite: Any metamagic feat.
Benefit: You can modify an area spell by changing the area's shape to
either a cylinder (10-foot radius, 30 feet high), a 40-foot cone, four
10-foot cubes, a ball (20-foot-radius spread), or a 120-foot line. The
sculpted spell works normally in all respects except for its shape.
For example, a lightning bolt whose area is changed to a ball deals
the same amount of damage, but affects a 20-foot-radius spread. A
sculpted spell uses a spell slot one level higher than the spell's