Below are the titles for the levels of HL and OF, with the names of the maps.
The command in the console is:
'map [mapname without .bsp]' (without the ')

-------------------------------
HALF-LIFE
(96+7 Maps) (Game+Hazardcourse)
-------------------------------
HAZARD COURSE
GEFAHRENKURS
T0A0.BSP
T0A0A.BSP
T0A0B.BSP
T0A0B1.BSP
T0A0B2.BSP
T0A0C.BSP
T0A0D.BSP

BLACK MESA INBOUND
AUF DEM WEG NACH BLACK MESA
C0A0.BSP
C0A0A.BSP
C0A0B.BSP
C0A0C.BSP
C0A0D.BSP
C0A0E.BSP

ANOMALOUS MATERIALS
ANOMALE MATERIALIEN
C1A0.BSP
C1A0A.BSP
C1A0B.BSP
C1A0C.BSP
C1A0D.BSP
C1A0E.BSP

UNFORESEEN CONSEQUENCES
UNVORHERGESEHENE KONSEQUENZEN
C1A1.BSP
C1A1A.BSP
C1A1B.BSP
C1A1C.BSP
C1A1D.BSP
C1A1F.BSP

OFFICE COMPLEX
BšROKOMPLEX
C1A2.BSP
C1A2A.BSP
C1A2B.BSP
C1A2C.BSP
C1A2D.BSP

"WE'VE GOT HOSTILES"
"FEIND IN SICHT"
C1A3.BSP
C1A3A.BSP
C1A3B.BSP
C1A3C.BSP
C1A3D.BSP

BLAST PIT
EXPLOSIONSKRATER
C1A4.BSP
C1A4B.BSP
C1A4D.BSP
C1A4E.BSP
C1A4F.BSP
C1A4G.BSP
C1A4I.BSP
C1A4J.BSP
C1A4K.BSP

POWER UP
ENERGIE
C2A1.BSP
C2A1A.BSP
C2A1B.BSP

ON A RAIL
AUF SCHIENEN
C2A2.BSP
C2A2A.BSP
C2A2B1.BSP
C2A2B2.BSP
C2A2C.BSP
C2A2D.BSP
C2A2E.BSP
C2A2F.BSP
C2A2G.BSP
C2A2H.BSP

APPREHENSION
FESTNAHME
C2A3.BSP
C2A3A.BSP
C2A3B.BSP
C2A3C.BSP
C2A3D.BSP
C2A3E.BSP

RESIDUE PROCESSING / QUESTIONABLE ETHICS
RšCKSTANDSVERARBEITUNG / FRAGWšRDIGE ETHIK
C2A4.BSP
C2A4A.BSP
C2A4B.BSP
C2A4C.BSP
C2A4D.BSP
C2A4E.BSP
C2A4F.BSP
C2A4G.BSP

SURFACE TENSION
OBERFLŽCHENSPANNUNG
C2A5.BSP
C2A5A.BSP
C2A5B.BSP
C2A5C.BSP
C2A5D.BSP
C2A5E.BSP
C2A5F.BSP
C2A5G.BSP
C2A5W.BSP
C2A5X.BSP

"FORGET ABOUT FREEMAN!"
"VERGISS FREEMAN!"
C3A1.BSP
C3A1A.BSP
C3A1B.BSP

LAMBDA CORE
LAMBDA-KERN
C3A2.BSP
C3A2A.BSP
C3A2B.BSP
C3A2C.BSP
C3A2D.BSP
C3A2E.BSP
C3A2F.BSP

XEN
XEN
C4A1.BSP
C4A1A.BSP
C4A1B.BSP
C4A1C.BSP
C4A1D.BSP
C4A1E.BSP
C4A1F.BSP

GONARCH'S LAIR
GONARCHS VERSTECK
C4A2.BSP
C4A2A.BSP
C4A2B.BSP

INTERLOPER
EINDRINGLINGE
C4A1A.BSP

NIHILANTH
NIHILANTH
C4A3.BSP

ENDGAME
SPIELENDE
C5A1.BSP

---------------------------
OPPOSING FORCE
(43+5 maps) (Game+Bootcamp)
---------------------------
BOOT CAMP
TRAININGS-CAMP
OFBOOT0.BSP
OFBOOT1.BSP
OFBOOT2.BSP
OFBOOT3.BSP
OFBOOT4.BSP

INCOMING
ANKUNFT
OF0A0.BSP

WELCOME TO BLACK MESA
WILKOMMEN IN BLACK MESA
OF1A1.BSP
OF1A2.BSP
OF1A3.BSP
OF1A4.BSP
OF1A4B.BSP

"WE ARE PULLING OUT"
"WIR ZIEHEN UNS ZURšCK"
OF1A5.BSP
OF1A5B.BSP
OF1A6.BSP

MISSING IN ACTION
VERMIST
OF2A1.BSP
OF2A1B.BSP
OF2A1.BSP
OF2A1B.BSP
OF2A2.BSP
OF2A3.BSP

FRIENDLY FIRE
UNTER FEUER
OF2A4.BSP
OF2A5.BSP
OF2A6.BSP

WE ARE NOT ALONE
WIR SIND NICHT ALLEINE
OF3A1.BSP
OF3A1B.BSP - alternate end of game (when you follow Gordon into the teleporter)
           - Alternatives Spielende (wenn Du Gordon in den Teleporter folgst)

CRUSH DEPTH
DIE TIEFE
OF3A2.BSP
OF3A4.BSP
OF3A5.BSP
OF3A6.BSP

VICARIOUS REALITY
GEFŽHRLICHE REALITŽT
OF4A1.BSP
OF4A2.BSP
OF4A3.BSP

PIT WORM'S NEST
WURMLOCH
OF4A4.BSP
OF4A5.BSP

FOXTROT UNIFORM
FOXTROT UNIFORM
OF5A1.BSP
OF5A2.BSP
OF5A3.BSP
OF5A4.BSP

"THE PACKAGE"
"DAS PACKET"
OF6A1.BSP
OF6A2.BSP
OF6A3.BSP
OF6A4.BSP

WORLDS COLLIDE
WELTUNTERGANG
OF6A4B.BSP
OF6A5.BSP

CONCLUSION
SCHLUSSFOLGERUNG
OF7A0.BSP

----------------

P.S.: Find out your skill level with 'skill' in the console
(set with 'skill x' where x :=
0 - easy
1 - normal
2 - hard)

----------------

tip: you can use the pageup / pagedown keys to scroll in the console
Just like in Quake 1-3

----------------

A big thanks to:
Valve
Gearbox
Sierra
ID Software (for the Quake engine)
robert.friedel@12move.de (german levelnames of OF)

----------------
Rolf H. Viehmann
RolfHub@gmx.net