This is the first installment of Style in Season, where we scour some of our favorite designers and websites for the most body-flattering and stylish options for all kinds of weather.

We firmly believe that a good jacket is a true investment piece. In the best case scenario, it should be fitted, stylish, sexy, and last for years – so you can afford to spend a little more, knowing it will be back winter after freezing winter.

The hardest part of finding a great jacket, we’ve found, is shape: what will look best with each of our body types?  What will accentuate our curves without restricting movement?  Will a jacket fit our bust, waist and hips?

There’s one surefire way to avoid those uncertainties: look for jackets that feature a belt.

We saw a lot of belted jackets hit the runways earlier this year, internationally, in the Fall/Winter 2009 collections. There were collarless coats with belts, trenches with belts, architectural coats and voluminous coats… It’s hard to go wrong.

Below are our favorite belted jackets of the season, along with the body types we think they’d fit best.

New York & Company Women’s City Style Plaid Trench – Cooling Cranberry, Weakening Brown
$79.95

Did you think you could do the plaid trend and a trench for under a hundred bucks? Neither did we, but this jacket proves us all wrong.  It would look great on almost every body type, though apple girls may want to avoid such a heavy collar.  You must check it out in brown – we love the way it’s styled.

ModCloth Carmen Trench
$107.99

We both immediately fell in love with this fantastic collar, and the way it’s styled with the belt tied instead of buckled.  (Options, ladies!)  This is truly a waist-lengthening jacket, and would look especially great on hourglass and apple figures.

Guess by Marciano Nadjia Trench
$228

We’re both suckers for the idea of “cozy”, and with this sweater, it looks like it would be pretty effective. Plus, with a faux leather belt, you could feel comfortable wearing it out to grab a drink or get some dinner. Hell, we’d even wear it on a date! (If we weren’t both already in terrific relationships, of course…). We love the brown, but the black sends out messages of “vixen” that we just can’t ignore. Great for almost all shapes, but especially straight and hourglass girls.

Plaid Ponte Jacket
$34.99

There’s no reason that your belted coat can’t be a short one! Particularly for girls with straight, or pear figures. The vibrancy of this pattern will definitely attract attention, but not in a Lady Gaga way, no… In a “damn, that girl is rockin’ some curves and confidence!” way. Yes, the lines on this jacket will give the illusion of curves – a nice bonus any way you look at it!

Spiewak Perrin Coat in Black
$195

Sometimes, simple is just… better. A classic trench like this wool one from Spiewak will last for years, literally. You will be able to wear it season after season – chances are slim that coats like this will ever be “out of style”. Plus, look at the details on the sleeve!

Ben Sherman Hillman Coat
$259

Jennifer adores almost everything by Ben Sherman, and this jacket is no different.  The houndstooth pattern is classy, yet eye-catching, and the hip-skimming cut is perfect for petite girls and short waists.

Do you think we picked the right jackets for your body shape?  Which jacket is your favorite?