Alot of the different series, are considered alternate universes. Like the movie, it's an alternate universe from everything else. When it comes to G1(the original series), the series that are connected to the cartoon, are Beast Wars, Beast Machines, & War Within. However, there are some things, mainly in War Within, that don't totally fit continuitywise with the original cartoon, mainly because I think Marvel owns the old cartoons & comics, so, there's some stuff they just can't do anymore. Oh, back on Beast Wars, the new comics are also included with G1, which also go into other characters & their original Cybertronian vehicle modes(their only Beasts, because of the planet they are on, the only modes that would work well to blend in, is animals).
Then Robots in Disguise is it's own series(though some have tried to fit it in with Armada, but, I don't think that works. Armada, Energon, & Cybertron are all one universe.
There's other series, like Evolutions, which so far, has only been one series of 6 comics, where, it's a "what if the Autobots & Decepticons awoke during the industrial revolution, instead of the 1980's". There's also some Transformers vs. GI Joe, & GI Joe vs. Transformers, which are all pretty cool, but are again, seperate universes. Basically, like super heroes, they have a multiverse. I'd really like to see some kind of continuation of G1's universe in animated fashion......maybe they could right the wrongs that was Beast Machines(overall, it's kind of a cool series, but, Cybertron became techno-organic at the end
On Megs, yeah, he's great, I have him, but, Hasbro apparently won't be bringing him over, so, I had to import. They did just release Masterpiece Starscream however, as a Walmart exclusive, I'm still looking for him. Here's some pics
Oh, the Dinobots. The ones that are tanks, are from War Within, which as I stated before, happens before G1, when they still have their Cybertronian modes. And to keep their group the same, they are called the Dynobots. Kinda cheesy, but, oh well. Oh, Swoop however is not a tank, but some kind of futuristic ship.
Here's a fanmade 3D rendering of the Dynobots alt modes(Here's the page I got these from
http://10fingersdesigns.com/3d/autobots25.htm) and robot modes