I feel dirty discussing min-max in public, but call me masochistic, it's just damn interesting to me. In my time with 3E, I've seen the same level combinations for min-maxing before taking a first level in a prestige class between levels 6 and 10. It seems to me that there are definite breaking points for multiclassing when grabbing all the abilities possible before a PrC, and losing the minimum BAB/Saves. Here's what I've noticed as far as useful levels:
Barbarian: 2 Levels is perfect. You get Fast Movement, a Rage, and Uncanny dodge. Skills list is good, so you can use class skill points to improve perception skills and possibly Wilderness Lore.
Bard: Not that great for multiclassing. 1 or 2 levels might work for the save increases, and music. The hit to BAB is rough though, and you still only have level 1 spells.
Cleric: Like Bard, 1 or 2 levels for the saves is good, but this doesn't mix too well with non-Cleric classes.
Druid: Never seen a multiclass Druid. All the good abilities come later, so it's not really worth the restrictions on weapons and armor to get the early ones.
Fighter: 2 or 4 levels is good. I mostly see 2 levels for the 2 bonus feats, but 4 levels gets you a Weapon Specialization. 3 levels is bad because you get nothing at 3 except your poor saves. I lean towards 2 because it'll never hit you with a multiclass penalty and the next two levels net you +1 to all saves and one feat... I can do better than that.
Monk: 1 or 4 levels is good. All the cool bonuses at level 1 are good, and by level 4 you've increased all your saves to +4, and got faster movement and 1d8 unarmed damage, plus some other minor abilities. Since you've already lost the 1 BAB at level 1, 2-4 are kind of a free ride.
Paladin: Bad for multiclassing. LG restriction, mainly. 1 level is good, if you can get a decent Cha. That save bonus is amazing. The class declines from there unless you're in it for the long haul.
Ranger: 1 level is best, unless you use Monte Cook's alt.ranger. Then 4 is good.
Rogue: 3 is the magic number. At 1, you gain +1d6 sneak attack but no BAB. At 2 evasion, but no offense. At 3, Uncanny Dodge and another sneak attack die. 4 is nothing, and at 5 you lose a 2nd BAB.
Sorceror: Best choice for arcane spellcaster multiclassing. You'll never have powerful spells, so you might as well get a lot per day. You also gain a BAB at the same time you gain a new spell level, so even numbers in Sorc are good. That said, I usually pick 2 or 4. Only drawback is the Cha dependency. That means you have to either pick a physical dump stat or Wisdom if you still want enough skills to play with.
Wizard: Not good for multiclassing. Numbers get all messed up with BAB, spell levels and saves.
My main goal with this is to minimize the levels with +0 BAB, and the levels with no class abilities. The main problem with this approach is low Will saves, but it's usually 2 points at the maximum.
On an aside, I hope Revised 3E keeps track of the fractional ability gains, and hurts the +2 to good saves at first level syndrome. It would make a world of difference when multiclassing in the non-warrior classes. Does anyone else notice little trends like this as far as low-level class balance?
Barbarian: 2 Levels is perfect. You get Fast Movement, a Rage, and Uncanny dodge. Skills list is good, so you can use class skill points to improve perception skills and possibly Wilderness Lore.
Bard: Not that great for multiclassing. 1 or 2 levels might work for the save increases, and music. The hit to BAB is rough though, and you still only have level 1 spells.
Cleric: Like Bard, 1 or 2 levels for the saves is good, but this doesn't mix too well with non-Cleric classes.
Druid: Never seen a multiclass Druid. All the good abilities come later, so it's not really worth the restrictions on weapons and armor to get the early ones.
Fighter: 2 or 4 levels is good. I mostly see 2 levels for the 2 bonus feats, but 4 levels gets you a Weapon Specialization. 3 levels is bad because you get nothing at 3 except your poor saves. I lean towards 2 because it'll never hit you with a multiclass penalty and the next two levels net you +1 to all saves and one feat... I can do better than that.
Monk: 1 or 4 levels is good. All the cool bonuses at level 1 are good, and by level 4 you've increased all your saves to +4, and got faster movement and 1d8 unarmed damage, plus some other minor abilities. Since you've already lost the 1 BAB at level 1, 2-4 are kind of a free ride.
Paladin: Bad for multiclassing. LG restriction, mainly. 1 level is good, if you can get a decent Cha. That save bonus is amazing. The class declines from there unless you're in it for the long haul.
Ranger: 1 level is best, unless you use Monte Cook's alt.ranger. Then 4 is good.
Rogue: 3 is the magic number. At 1, you gain +1d6 sneak attack but no BAB. At 2 evasion, but no offense. At 3, Uncanny Dodge and another sneak attack die. 4 is nothing, and at 5 you lose a 2nd BAB.
Sorceror: Best choice for arcane spellcaster multiclassing. You'll never have powerful spells, so you might as well get a lot per day. You also gain a BAB at the same time you gain a new spell level, so even numbers in Sorc are good. That said, I usually pick 2 or 4. Only drawback is the Cha dependency. That means you have to either pick a physical dump stat or Wisdom if you still want enough skills to play with.
Wizard: Not good for multiclassing. Numbers get all messed up with BAB, spell levels and saves.
My main goal with this is to minimize the levels with +0 BAB, and the levels with no class abilities. The main problem with this approach is low Will saves, but it's usually 2 points at the maximum.
On an aside, I hope Revised 3E keeps track of the fractional ability gains, and hurts the +2 to good saves at first level syndrome. It would make a world of difference when multiclassing in the non-warrior classes. Does anyone else notice little trends like this as far as low-level class balance?