I wouldn't want to "have" to play a multiclass character to have all the bases covered. A 3-character party (2 PCs, 1 NPC) can easily cover almost all the bases with characters that are a little more generalized and a little less specialized. And with a little DM consideration from time to time (like making healing potions available for a party with low healing resources), it shouldn't be a problem.
DON'T multi the cleric. Clerics are already generalized enough to be able to play different roles.
The Ranger is a great utility character, and can cover combat, stealth, and even healing (with the right wand).
Bards also have great variability, but the bard should still try to focus on one or two areas, and not try to cover everything.
Just about the only straight multiclassed figure that I would consider would be a rogue/wizard, and even then, I'd rather aim for the Arcane Trickster.