Which version of 184.108.40.206 engine will suit you completely?
(Obsolete since february 2013, check february'2013 1122 patch)
Current build (Steam):
Most close to the original No-Steam versions - are these:
Anything else that you can find in the Internet includes additional unnecessary models, repainted to extreme tone menus, background image "Vasya Pupkin© edit", and maybe even cheats and viruses.
v.36 - this is the same v.35, but only with the 48 protocol. The vast majority of No-Steam servers are currently using protocol 47, or 47/48 multiprotocol, so if you take 48 proto version, you can not get in to some servers. Legit steam-servers will not allow this connect anyway:
Latest stable version with 48 protocol - this is an update through HLClientUpdater (aka DUDe). By the way, it can download the whole client from scratch =):
UPD 2012: Project DUDe now dead, you can download last multiprotocol at yadi.sk or at google.com