I've had the following connections (yes, I've owned seperate pieces of equipment capable of a maximum of the following):
*55bps Baudot (5 bits per character) TDD connection
*110bps ASCII (7 or 8 bits per character) TDD connection (it was amusing checking e-mail on a 40 character, 1 line display)
*!300bps modem - Hayes?
1200bps modem - Hayes?
!2400bps modem - Packard Bell
*9600bps modem - Teleblazer I think
!14.4kbps modem - Teleblazer I think
19.2kbps modem - NexCom 300vi (TDD/modem combo)
28.8kbps modem - Motorola
33.6kbps modem - Motorola
!33.6kbps modem - Whoever made those wonderful Packard Bell combo cards. Aztech?
56kbps modem - Aztech
64kbps ISDN connection VERY briefly (and wasn't mine technically) - I forget the manufacturer
!512/64kbps cable modem - Prime Cable, Com21 ComPort
!512/128kbps cable modem - Prime Cable/Cox Communications, Com21 ComPort
!1.5/384 RADSL - Sprint/Earthlink, Alcatel modem.
!768/768 SDSL - Covad/Speakeasy, Efficient SpeedStream modem.
* = Never connected to a "real" ISP through this connection (BBSes with Internet connections not counted)
! = I still own this piece of equipment.