I figured I'd throw in my two cents since no one's suggested a build like this yet. DISCLAIMER: This build is a bit wonky.
Hybrid Taric focused on building attack speed to abuse Q cd reduction. Just look at his kit: he can utilize Triforce better than almost any other champ (Q spam for procs, high base damage, likes the slow, can use the mana and the AP, loves the attack speed).
First of all, I only ever bother to play Taric when the other team has a lot of melee champs, he's just not strong enough against ranged, especially ranged AP. You also need pretty decent damage on your team, but at the same time, you can't be the sole tanky champ. If that sounds restrictive... well, it is, but I consider Taric a niche champ on Dominion anyway. And note that 3+ melee on the enemy team is VERY common in dominion.
My core is glacial shroud + Triforce + Rageblade. I favor Tabi when appropriate, otherwise grab cdr boots or merc treads if you need the cc reduction (rare, b/c no one wastes cc on Taric). Expensive, but he starts to get strong with just Glacial + Zeal. If the game drags on, you will be able to 1v1 almost anyone, and you still have all of Taric's normal utility, making you a great asset in teamfights. If the game REALLY drags on, grab more tanky items or even a phantom dancer.
How to play him: stun an enemy carry whenever they get into range. Walk up to the NEAREST TARGET (a squishy is best, but you cant always close the gap) and start spamming Q. Constant triforce procs + stun + slow + your boosted attack speed means you will be throwing out heals every 2 or 3 seconds very reliably while dealing surprising damage. If your team gets wiped, you can 1v1 any melee champ short of Jax or a fed skarner. 300+ self-heals every 3 seconds gives you insane 1v1 sustain without buying any lifesteal at all.Get ready for some hilarious reactions when you 1v1 that fed enemy Pantheon or Wukong.
Is this the best way to play Taric? I have no idea, but it's a lot of fun in my opinion, and if you're playing Taric you're looking to be outrageous, not OP.
Edit: masteries and runes can make a big difference on Taric. 15/15/0 hybrid masteries. Hybrid or Armor Pen reds, flat armor yellows, flat CDR blues (or cdr/level if you dont want to splurge on those stupid 820 IP runes), and movespeed Quints. Mpen runes aren't a bad choice, since they make the most difference early game, and your only damage source is spells until you finish Glacial Shroud. Note that with the offensive + defensive cdr talents and CDR blues will get you nearly 20% CDR by level 18, making Glacial shroud the ONLY cdr item you need to reach cap. Makes lucidity boots a bad option, i just mentioned those in build in case you don't want this runes/masteries setup.
Edit2: Wow, wall of text. Maybe I should try perfecting this build and write a guide >_<