After the intro to my garage it is fitting that I talk about the tanks I love best. I don't like all of them but there are 2 reasons I keep the ones I dislike. First, I don't need the garage space right now. I still have free slots so there's no need to sell those tanks. Second, it is possible that more tanks will be added at some point in the future, which branch off from some of the ones I already have. If I sell them, I won't be able to research those new tanks unless I buy the previous tanks back. Granted, this last scenario is becoming more unlikely as time goes by, especially since the Russian tree, for example, is full, and so is the US tree. But enough chit-chat. Here are my favorites.
USA
Tier VI
M4A3E2 "Jumbo" Sherman
I like to run the "Jumbo" with the 105mm howitzer. Why? Because that gun can deal damage even to tier IX-X tanks. While the 76mm M1A2 gun is very sweet with its fast firing rate, it will never penetrate tanks VIII and above from the front. Yes, I know you're supposed to flank but that's not always an option, especially when the Jumbo isn't the fastest medium tank around. I prefer the Jumbo over the simple M4 because the former has some very nice armor that can often bounce shells from high level tanks, while the M4 has paper armor in comparison.
M18 Hellcat
The Hellcat is a fairly recent acquisition and its crew is only 94% or so. Yet, I prefer it to the M36 Slugger (which used to be one of my favorite tanks before the M18) and that's mostly because of the speed. There's a huge grin on my face when my Hellcat goes 72kmph. This makes it perfect for quick hit-and-run scenarios. Unfortunately it does have some weaknesses, namely the average acceleration, slow turret turning speed and paper-thin armor. The 90mm gun, though, is a monster on that little tank and it can put some serious hurt to high level tanks.
Tier VII
T29
This is by far my favorite tier VII tank and it is a strong contender for my favorite tank ever. Strangely, I run this tank with the 90mm gun instead of the 105mm. Why? Because the 90mm is a lot cheaper to operate for a non-premium player. The 105mm is a very nice gun but I found myself losing credits whenever I used it. The funny thing is that the higher penetration of the 105mm doesn't guarantee that the shell won't bounce, meaning that each failure to penetrate costs me 1000 credits. I only run this gun when there's a weekend promotion or such. But the main reason I love the T29 is because the turret is nigh-invincible. The hull might be weak but the T29 excels at hull-down and that's how I love to run it. Using hull-down and the "puny" 90mm gun I have defeated much stronger tanks. Apart from this, the T29 is fairly mobile for its size and can equip a Vertical Stabilizer which allows it to scoot-and-shoot very effectively.
Germany
Tier III
Marder II
The Marder II is in the top 3 of my best tanks. This little tank destroyer is a beast, when played right. It has the widest gun traverse of all TDs (with the exception of turreted TDs, of course) and the 76mm gun is incredible for its tier. Besides, the matchmaker is kind to it, most of the time matching it up with tier V tanks or below. There aren't many tanks which the Marder II meets in battle that it can't penetrate. With the Marder II I've had some of my best performances, including 9 kills in one battle, and it also has my highest win ratio, at 61%. One other advantage of this tank is the excellent camouflage, especially with a Camo Net.
Tier V
Panzer IV
The Panzer IV was an iconic tank in WWII and it is one of the best tier V tanks in World of Tanks. While the armor is weak and the mobility is low, this tanks excels in the role of sniper, and that's how I play it. The 75mm L/70 gun is very accurate, loads quickly and can penetrate most of the tanks it faces. The PzIV also manages to camouflage very well.
Tier VI
GW Panther
The GW Panther SPG is my newest acquisition but the crew is at 97% (in addition to 55% Brothers in Arms) because I transferred it from the Hummel. While the Hummel was a fun (and occasionally frustrating) tank to play, the GW Panther is even better. I love it primarily because it has the widest gun traverse of all SPGs, which makes for accurate and quick re-targeting. The top gun is decent and I love the fact that I can hurt tanks all the way to tier X, though I can't normally one-shot them, unless I land a very lucky shot. If push comes to shove, the GW Panther can also switch to TD mode, almost as good as the Hummel.
Tier VII
Panther and Tiger
I will mention both these tanks together here because I love both but not as much as I love other tanks. However, they are both iconic WWII tanks and each of them has a very sweet gun. The Panther's 75mm L/100 and the Tiger's 88mm L/71 are both incredibly accurate and make these two tanks great snipers. Unfortunately, they both suffer from poor armor and must be played in a support role unless they are top tier. Even then, it's not advisable to lead the charge. Whenever I have a Tiger in my GW Panther's sights I think "poor little Tiger".
France
Tier VI
ARL 44
In only have 3 French tanks out of which I only kind of like the ARL 44. The truth is that I like other tanks more but I felt like I should at least mention the ARL 44. The tank itself is quite weak, especially the turret. The hull can take a few hits and it can even bounce some from the front. The tall tracks can also absorb hits occasionally. But the top 90mm gun (DCA 45) is very accurate and its 212mm penetration is the highest of all tier VI tanks. Then again, this is a tier VIII gun on a tier VI tank. I love the gun but this heavy tank must be played as a sniper, or in a support role because it can't take too many hits.
USSR
Tier III
SU-26
The SU-26 is the only SPG in the game that has a 360 degree turret and that's the main reason why I love this little artillery. The tank does have some serious flaws, including a very slow speed, reduced attack range and low shell damage, but it makes up for these with the accuracy of its gun, the turret, the fast firing rate and the high shell arc. This little SPG is a lot of fun to play and the matchmaker is generally kind to it, though I've had plenty of games in which I was matched with T29s. However, the high shell arc makes it easy to target the top of the hull, where the armor is thinnest.
Tier V
SU-85
I've heard many people hating on this tank destroyer but I'm not one of them. I love the SU-85 because it has decent mobility, good camouflage and the 107mm gun hits hard. It is not the most accurate tier V gun but when it hits, it hits like a truck. I've had many glorious battles in the SU-85. Besides, I saw one in real life.
Tier VI
KV-2
Until last week, this used to be called, simply, the KV. But they rightly split it into KV-1 and KV-2. Unfortunately the KV-2 was moved from tier V to VI and now faces higher tier tanks in most battles. It was good while it lasted but the KV-2 is still one of my absolute favorite tanks due to the 152mm howitzer gun. Yes folks, you heard it right, I rock the 152mm "derp" on my KV-2 and I've been rocking it for a very long time. This gun makes the tank play like no other and it also racks in the credits. The massive 700 damage from the HE shell will hurt even tier X tanks, which means that I don't have to worry about penetrating their thick armor. Yes, the tank is slow as molasses, the turret even more so, and the gun takes ages to reload, but if you know all these limitations you can easily work around them. For example, I run Improved Ventilation, Gun Rammer and Gun Laying Drive. Because shells are expensive, I take my time to aim and then hide immediately after I fire, until I finish reloading. Many tanks, even high tier ones, get scared when they see me round the corner with the 152. But thanks to this gun, if I can get even 1 good hit in a battle, I am guaranteed a profit. While profits used to be higher before the split, they are still very good now.
So these are a few of the tanks I like best. Many of them are parked though, and I only play them rarely, when there's a 5x experience promotion. These days I mostly play the GW Panther, KV-2, T29 and M18 Hellcat.