In the short term, i.e. A quick battle, does one have an advantage over the other? I'm trying to decide if using the Spellbreaker or a good shield with a high magic resistance would be best.

Spellbreaker completely blocks shouts, even from dragons.

What Glargg said... plus wards take a second to charge up.. and shields can be used to bash, so it's like having a secondary weapon in your hand.

Plus Wards eat magicka leaving you with flat batteries......then waddya gonna do huh.......Ward fails, no magic, no shield, no life........

Also, I know some people swear by Spellbreaker......but it's not the only good shield. Any good quality shield,,like glass, highly smithed and with the elemental protection perk will be more than good enough. Plus you can add a couple of extra enchantments of your own to it.

Ulda's top shield is her Bespoke 'Laas Vahlok' with an AR of over 120, + block 47% + extra health 72pts and the Block Runner perk.....meaning it already also has elemental protection 50% and deflect arrows. She can hide behind this baby all day in the face of a Legendary Death Overlord with an ebony battleaxe........or raise it and run directly at shock mage, bash him and put him down.

I guess that means I prefer shields then

My main sword/board character, Herricka, is just as deadly with Spellbreaker as she is with Dawnbreaker. She fights mages with just the shield, bashing them to death, and consequently hardly ever gets hit. And she fights dragons with a combination of the shield and shouts, running in and bashing them when they land.

What you're saying is probably true for Legendary. When playing at Adept, Spellbreaker is already plenty overpowered. You simply don't need any better shield at that difficulty. It will stop almost everything that a mage, draugr, or dragon can throw at you, and by perking the bashing side of Block, it becomes a deadly weapon.

Almost always i stick with passive stats than with active abilities, if the possibility exists, in all RPGs. So Magic resistance > Spell Breaker / Ward

Resist Magic caps at 85%, though.

Shield of solitude if you're going 'all in', with some other sources of magic resist, otherwise spellbreaker is better.

Yeah, my current playthrough is pretty much dedicated to the Shield of Solitude for the magic resistance.

As for wards vs. magic resistance, Deathlords can be a real pain in the neck if they are using Fus Ro Dah or Disarm. Fortunately, that doesn't come up very often. Spellcasters who hide behind wards are also annoying because I've recently started enjoying luring baddies up to a height and blowing them off. It's very disappointing when a ward negates the shout. But to answer the question, I'm going with magic resistance and the Shield of Solitude though SpellBreaker is a tempting second...