Some members have said they liked the DieHard Platinum Automotive battery. Thought I'd get one. I think the G37 takes a Group 35, it's like ~$220.00 regular price, Sears has it at ~$155.00 today, online, store pickup if you're looking for one. Here's a link:
Car Batteries on Sale

 

$220 or even $155 is WAY too much for a Group 35 battery. Just my .02

 

$125 for an optima yellow top sounds better to me:

Optima YellowTop 12V AGM Car Battery for $125 after rebate + pickup at AAP - DS46B24R

it says for prius, but using the same code and rebate you should be able to apply it to the correct battery

 

Specs from the web site:
Product Description

THE MOST POWERFUL AND RELIABLE DIEHARD PLATINUM AUTOMOTIVE BATTERY EVER!

• 4-year FREE Replacement, 100 Month Pro-Rated Limited Warranty

• 740 CCA (Cold Cranking Amps) - Reliable starting power in all weather conditions, due to the use of 99.99% pure virgin lead plates and tin-coated brass terminals

• 100 Minutes of reserve capacity - Ideal for luxury vehicles with multiple electronic accessories

• Longer off-season storage time – Ideal for show cars & classic cars

• AGM (Absorbed Glass Mat) construction - Provides mounting flexibility & guarantees longer service life

• Worry and maintenance-free operation - High purity grade acid held safely in place by glass mats makes a non-spillable design that gives mounting flexibility

• Military-grade construction & proven vibration resistance – Ideal for off road applications
  (Probably best to stay on the road tho? :-)

 

The die hard platinum is a rebadged odyssey battery which one of the best commercial batteries avail. Much better battery than the optima red/yellow/blue tops.

 

It appears the sale was only a one day deal. :-( I hope a forum member or two saved some bucks.