The company used Mobile World Congress show in Barcelona to unveil the Desire and Legend for Android 2.1, and the HD Mini for Windows Mobile.
As part of the launch, the company also revealed that it has revamped its Sense overlay seen originally on its popular Hero handset.
New features include broad improvements to the browser, an email client and other functions, as well as the ability to 'leap' between screens by pinching the display. This brings up thumbnails of each of the seven home screens that Sense offers on Android.
The update also introduces the HTC Friend Stream, an application and widget combination that aggregates Facebook, Twitter and Flickr into one organised flow of updates. Contacts can be organised into specific social circles, such as groups of friends or colleagues.
The HTC Legend takes after the Hero in terms of form factor, but the case is now made from a single piece of turned aluminium. The screen has been upgraded to a 3.2in Amoled HVGA display, and the trackball has been replaced with an optical joystick.
The HTC Desire, meanwhile, is aimed at the audio visual crowd, packing in a 3.7in Amoled display, a 1GHz Snapdragon processor and full Flash 10.1 support. As with the Legend, the Desire includes an optical joystick.
"HTC Sense was created to magnify your ability to create and define your own unique mobile experience," said HTC chief executive Peter Chou.
"HTC Legend and HTC Desire take Android to another level in substance with HTC Sense, and style with the Legend's revolutionary crafted aluminium unibody design."
Chou added that the new version of Sense will also be coming to some of HTC's existing handsets, including the Hero in Europe and Asia.
The Legend will be available in Europe through Vodafone and the direct channel from April, and will roll out to other parts of the world in the early second half of the year, alongside the Desire which will be launched around the same time.
Third on the list is the HD Mini, a smaller version of the popular HD2. Running Windows Mobile 6.5, the handset packs in all the same power and features as its big brother, but in a smaller form factor and using the latest version of Sense.
"The demand for the HTC HD2 has exceeded our expectations, and the HD Mini fulfils a desire from some customers to bring the capabilities and experience of the HD2 to a more compact design," said Chou.
The HD Mini will be broadly available to customers across major European and Asian markets in April.
Lastly, Chou announced that HTC has taken Microsoft chief executive Steve Ballmer's message to heart and will be releasing smartphones based on Windows Phone 7 later this year, although no details beyond that were given.