All Hasbro's site - not updated at all. But it is the official site.
The official site for the official Transformers convention, Botcon.
Elsewhere on the Net:
Ben Yee's excellent Transformers web site. Has numerous reviews, including a thorough guide to Transformers: Car Robots, the Japanese line from which Robots in Disguise is derived.
Mega-site featuring toy / television show news, transformers music, etc.
Features news and a photo archive of TFs. Excellent site.
General Transformers site, providing links to the newest images and news about new products.
RiD - Toy Fair 2001
Bobbi went to Toy Fair and got to see Transformers RiD toys before most of us. This is her report from Toy Fair 2001.
Botcon 2001 Report
Matt went to the 2001 Botcon. His report was featured on about.com.
Hidden Insignia Stickers Explained
The rub signs were just one thing that made Transformers more than meets the eye. Read an explanation of how they work.
On-line forum covering every aspect of Transformers out there. Need to register to post but not to read.
Japanese toy site, some Transformers content. Requires registration to view some content.
Reworks Transformers Parts Identification Aid
Has photos of many G1 and G2 parts for identification purposes.
Site includes downloads as well as scans of G1 instruction sheets.
Ravestrike's Sticker Restoration Page
includes sticker kits for G1, G1 reissues, RiD. Also has conversion kits to create "custom" figures.
Stickers worn on your TFs? Check out Deltastar's replacement stickers.
Botch's Transformers Box Art Archive
Features images of TFs as they appeared on packaging.
The Humble Transformers FAQ Page
Transformers FAQ site, includes links to several other Transformers FAQs.
Collectors Guide to Transformers
General Transformers toy site, not recently updated but has some good content, including a TF glossary of terms.
Transformers Encyclopedia, covering comic and television continuities for the US, UK and Japan. Very thorough.
Devvi's Transformers, Diaclone & Robotix Page
Nice site with bootleg TFs, pics of G1as well as some scans of original sticker sheets.
List of Transformers Toys
Listing of Transformers toys through Beast Wars. Thorough listing with many pics.
Has tech specs archive, photo gallery, reviews, fan fiction, and more.
PVC Figures Toy Archive
From Adam Pawlus's 16bit.com site, an overview of the first 2 PVC sets.
Air Raids Beast Wars Transformers Page
Has reviews and concept are for BW toys.
Provides a brief overview of the Beast Wars line, as well has having a BW boxscan archive, reviews and more.
Includes episode guides for both US and Japanese cartoons, complete toy lists, Botcon reports, etc. Nice site.
Complete American Variants Page
Variants don't just happen with the Star Wars line. A guide to American Transformers variants.
KIDkoRRuPt's Custom G1 Cars
Has a general guide to repainting, features repaints and kitbashes. Some nice repaints on this site.
In addition to an archive of Transformers, Transformerland has a nifty identification guide for loose parts and accessories. Also has an online store and a discussion forum.
General news site... offers news on new TF toys and products
Features episode downloads. What more needs to be said?
Unofficial Beast Machines Page
Beast Machines 2.com General information on TF:BM is found @ this site.
Online store with both domestic and import Transformers. Flat rate shipping!
Import toy store... lots of neat stuff here.
Hobby Link Japan
A Japanese based collectibles site with preorders for the latest Takara releases and reissues. Japanese based, so shipping is a little more expensive and takes a little longer, but prices are quite competitive (and in Yen).
Action Figure Express
Action Figure Express, general on-line toy retailer. Imports some TFs with pretty good prices.
Online retailer, both domestic and import Transformers.
Another import toy store.
Transformers Bust Club
An online store for busts and statues of Transformers.