Out of the all year-end lists we compiled, picking the top sedan of the year was quite honestly the most difficult of them all.

First of all, the choices are limitless compared to the other segments. Second of all, 2010 has been characterized as a year when sedans - be it entry level ones or luxury types - have become as popular as ever. And lastly, picking one over another has become a matter of preference - and to a certain extent, budget constraints.

For our list, we've narrowed it down to five models, all of which are worthy of being hailed as 2010's top sedan. In this list, three are of German descent, one is of Japanese origin, while the other is British-born. From our hints, you can probably surmise which models made it, but for the sake of suspense, we're not going to spoil anything.

Head over after the jump for the full details.

Fifth Place: Infiniti M

Infiniti’s new luxury model, the Infiniti M, actually made its debut at the 2009 Los Angeles Auto Show, although it qualifies on our ‘Best of 2010’ because it was officially released in showrooms at the early part of this year.

For the newest model, Infiniti offers two different powertrains for the M luxury class: a base level M37 with a 3.7-liter VVEL V6 engine that produces 330 horsepower and a higher-in-the-clouds M56 that comes with a 5.6-liter VVEL Direct Injected V8 engine, producing a stout 420 horsepower.

Both versions of the M Class luxury sedan come with either rear wheel drive or Infiniti’s Intelligent All Wheel Drive system, not to mention an array of advanced technology systems from the Japanese automaker, including Active Noise Control, Forest Air climate control, Infiniti Drive variable driving modes, Active Trace Control, Eco Pedal, and enhanced Infiniti Hard Drive Navigation System.

Fourth Place: Mercedes C-Class

The new Mercedes C-Class will only be unveiled by Mercedes in January 2011, but it’s already generating quite a bit of buzz heading into its debut at the Detroit Auto Show. For starters, the C-Class will be getting a new V6 engine that will come with 11 different power options ranging from 120 horsepower al the way up to 306 horsepower.

In addition to that, all models of the new C-Class, with the exception of the C300 CDI 4MAtic, will be outfitted with a new seven-speed automatic transmission 7G-Tronic Plus, which is set to become available in June 2011.

For a car that’s going to go on sale this March, the facelifted C-Class is already looking like it’s going to be formidable foe for the BMW 3-Series.

Third Place: BMW 5-Series Sedan

Speaking of BMW, the company’s next generation 5-Series luxury sedan made its debut in 2010 amid much fanfare. The new 5-Series’ design was given a complete overhaul with BMW using inspiration from both the 5-Series GT and the 7-Series limousine, giving the new 5-Series a more elegant and luxurious design language.

In terms of performance, the BMW will come with a number of different V6 and V8 powertrains in either gas or diesel fuel types. The base model of the 5-Series will be the 520d that will produce 184 horsepower while the 535i will be powered by a BMW TwinPower Turbo that cranks out 306 horsepower. Finally, the top-of-the-line 550i will have a V8 engine that produces an output of 407 horsepower.

Each of the variants of the new 5-Series will come with an eight-speed automatic transmission, as well as new features like EPS Electric Power Steering that takes some stress off the drive train by reducing parasitic drag and frees up a few more horsepower at the same time.

Second Place: Audi A7

The Audi A7 Sportback had a highly touted and much publicized debut earlier this year, opening up Audi’s portfolio with a vehicle that combines elements from an elegant coupe, a sport sedan, and a practical wagon. As far as powertrain, the five-door A7 Sportback comes in four different engine options – two gas and two diesel.

The base model will be a 2.8 FSI engine that produces 201 horsepower and 280 Nm of torque. There will also be a 3.0 TFSI engine with an output of 296 horsepower with 440 Nm of torque, a 3.0 TDI producing 210 horsepower with 400 Nm of torque, and lastly, a 3.0 TDI engine producing 242 horsepower with 500 Nm of torque..

For front-wheel-drive versions, the engines will be mated to a Multitronic CVT automatic whereas Quattro models will come mated to a seven-speed S tronic twin-clutch transmission.

First Place: Jaguar XJ

Arguably the most impressive sedan to come out in 2010 is Jaguar’s completely overhauled luxury vehicle, the XJ sedan. From the previous model, which didn’t do a whole lot for our imaginations, to a completely fresh 2010 model, the new XJ has been made to look a lot younger and more attractive than its predecessors.

And the best thing about the new XJ is that the sedan’s new styling is only the beginning of its overhaul. Under its hood is where it becomes a lot more interesting, thanks in large part to a number of powertrain options available for the luxury sedan. From a 3.0-liter V6 engine all the way up to a 5.0-liter V8 engine, the 2010 XJ will carry both naturally aspirated and supercharged versions with power ranging from 385 horsepower all the up to 501 horsepower.