Favorite Toy, by Series.

[Sokar]

Generation 1: Soundwave (never had prime, until the reissue, so can't really say prime)
Generation 2: G2 Prime
Beast Wars: Optimus Primal
Beast Machines: none collected really
Robots In Disguise: Omega Prime, or if you want to be picky, then Optimus Prime
Armada: Nemesis Prime
Universe 1.0: Nemesis Prime - never got the toy, but I do have big convoy, and I prefer the black and gold scheme of nemesis
Alternators: Laserwave
Energon: downshift
Cybertron: Optimus Prime/Galvatron (too hard to decide between the two)
Classics 1.0: Voyager prime - good articulation, interesting offshoot of the original design, and a great sculpt for the head
Movie: Concept camaro deluxe bumblbee
Animated: voyager prime
Universe 2.0: Powerglide - yes, I like him more than onslaught (though onslaught is incredible as well)
Masterpiece: Prime, though greenscream is my favorite of the seekers

[Incepticon]

Generation 1: tie between Shockwave & Soundwave. Dinobots & Omega Supreme close runner-ups.
Classics: tie between the Seekers & Bumblebee.
Movie: toss-up between Deluxe 08 Bumblebee, Leader Prime or Leader Brawl.
Animated: tie between Voyager Prime & Leader Bulkhead... and probably Leader Magnus once I get him
Universe: Onslaught
Titanium War Within: tie between Prime & Megatron
Titanium G1: tie between Magnus & Rodimus
Alternators: Hound
Masterpiece: Prime

[Bountyan]

Classics 1: Jetfire
Movie: Camaro Concept Bumblebee, 'nuff said
Animated: Voyager Optimus Prime, Prowl and Leader Bulkhead are up there too
Classics 2: Hard too say...probably Tankor

And yes, I haven't been a collector for long, only about a year now. I'm at about 60 figures.

[AnimeXHobby]

Generation 1: Optimue Prime(I love the trailer)
Beast Wars: Megatron
Robots In Disguise: Omega Prime
Armada: Unicron
Alternators: Mirage
Binaltech: Arcee (Newest one I got)
Energon: Omega Supreme
Cybertron: Optimus Prime
Classics 1.0: Too hard to choose. Basically all of them are my favourites especially Henkei Version.
Movie: Deep Space Starscream
Animated: Snarl, Prowl(Don't like most of them in the line.)
Universe 2.0: Silverbolt(Seriously, it is the best in the line so far), Prowl. Tankor is good, but too bad it isn't a Voyager.
Masterpiece: Megatron.

[aximili]

Generation 1: Soundwave
Generation 2: Megatron
Beast Wars: Depth Charge Runner-ups Inferno, Transmetal Tarantulas
Beast Machines: Jetstorm (deluxe), or can I count 6" Titanium Cheetor?
Animorphs: Ax/Scorpion
Armada: Starscream Runner-up Optimus Prime
Energon: Megatron
Cybertron: Starscream (voyager)
Classics 1.0: Jetfire Runner-up Grimlock
Movie: Brawl (leader) Runner-up Blackout, Optimus Prime (leader) & Megatron (premium leader)
Animated: Megatron (leader) Runner-ups Blackarachnia, Starscream, Bulkhead (leader)
Universe 2.0: Powerglide Runner-ups Onslaught, Octane
Masterpiece: Starscream

[Stoneclaw]

Generation 1: Tracks R/U Perceptor and Soundwave
Generation 2: Bruticus
Beast Wars: Inferno R/U Rhinox, (original and TM) Polar Claw and Megatron (Dragon)
Robots In Disguise: Optimus Prime
Alternators: Rodimus Runner-up: Tracks.
Classics 1.0: Soundwave Megatron, Jetfire, Bumblebee. Runner-ups: Astrotrain,
Movie: Ironhide
Animated: Grimlock. Runner-ups: Leader Megs
Universe 2.0: Onslaught. Runner-up: Prowl

[Silverbolt]

Generation 1: Aerialbot Skydive
Generation 2: Aerialbot Skydive
Beast Wars: Silverbolt
Beast Machines: Jetstorm (Ultra)
Robots in Disguise: Ultra Magnus
Armada: Starscream
Universe 1.0: Silverbolt
Alternators: Decepticharge
Energon: Cliffjumper
Cybertron: Excellion
Classics: Skywarp
Movie: Concept Camaro Bumblebee
Animated: Bumblebee
Universe 2.0: Onslaught

[Protoform X]

G1: Predacon Rampage
G2: Tank Megatron
BW: Insecticon
BW2: Galvatron
BW Neo: Big Convoy
BM: Skydive
MW: Optimus Prime
RID: X-Brawn
Armada: Supercon Prime
Energon: Rodimus
Cybertron: GF Prime
Movie: Starscream
Animated: Cybertron Mode Prime
Classics 1.0: Optimus Prime
Classics 2.0: Sunstreaker
Alternators/Binaltech: Jazz
MP: Optimus Prime

[Cheers Ian]

Generation 1: Power Master Optimus Prime
Generation 2: Megatron (Sold him a few years ago, regretting it now
Beast Wars: 10th Aniversary Optimus Primal.
Beast Machines: N/A
Robots In Disguise: Scourge (the only RID I own, heh)
Armada: N/A
Universe 1.0: N/A
Alternators: Shockwave (Shockblast)
Energon: N/A
Cybertron: N/A
Classics 1.0: Bumblebee
Movie: Leader Optimus Prime
Animated: Leader Bulkhead
Universe 2.0: Sunstreaker
Masterpiece: Optimus Prime
Japanese: God Bomber/God Ginrai

As you can see, I pretty much only collect G1 related/inspired stuff.

Cheers!
-Ian

[CorruptCayh]

G1: Soundwave
Beast Wars: TM2 Megatron (dragon)
Beast Machines: Scavenger
RID: Megatron
Armada: Megatron
Cybertron: Primus
Classics: Megatron
Animated: Lockdown

anything not mentioned.. don't have any favorites, or don't have anything at all ^^;