If money is not a problem which of these three would you choose? Is the trip by either bus or rail interesting enough to warrant the time or better to just go by plane?

As I recall, the car trip to "San Se" from Madrid took about 5-hours (more, because we stopped in LERMA and other places along the way) by car.

If I couldn't drive, I'd take the train. MUCH more comfortable than the bus but more expensive. Plane might be an even more expensive option but with all the security and "must be at airport 2-hours before flight" rules, waiting for luggage, flight time, etcetera it could actually take AS LONG as if by train and you can't see ANYTHING on the plane!

Anyone else have some bright(er) ideas?

Saludos, MadridMan

From what I can work out it looks like the bus will be the only option as it appears that only one train runs on sunday and it is an over nighter...

I'm looking at the RENFE site right now for the Madrid->SanSebastian trip and it shows:

DAILY TRAINS: (including Sundays)

Train: INTERCITY Leaves @ 10:00 Arrives @ 16:23 Price: 31 €

Train: Costa Vasca Leaves @ 22:45 Arrives @ 07:03 Price: 40.50 €

ONLY SUNDAYS:

Train: Talgo Leaves @ 15:19 Arrives @ 21:36 Price: 32 €

TAKING THE BUS:
The bus company that serves the MADRID -> SAN SEBASTIAN-DONOSTIA route is Continental-Auto . Here's there schedule:

(Leave Arrive Kms. Price Days)
Salida Llegada Kms. Precio Días Temporada Más
00:30 06:40 -- 468 - 25.84 LMXJVSD Todo el año
07:30 13:55 -- 468 - 25.84 LMXJVSD Todo el año
09:00 14:45 -- 468 - 25.84 LMXJVSD Todo el año
11:00 17:15 -- 468 - 25.84 LMXJVSD Todo el año
13:00 19:20 -- 468 - 25.84 LMXJVSD Todo el año
14:00 19:50 -- 468 - 25.84 ____V__ Todo el año
15:30 21:55 -- 468 - 25.84 LMXJVSD Todo el año
16:00 21:45 -- 468 - 25.84 LMXJVSD Todo el año
17:00 22:50 -- 468 - 25.84 LMXJVSD Todo el año
19:00 01:00 -- 468 - 25.84 LMXJVSD Todo el año
21:00 03:00 -- 468 - 25.84 ____V_D Todo el año

You're going on a SUNDAY so that's the "D" in the days listed. I see there are 9 buses per day and is only 25.84 €. And for most routes it seems to take about as long as a train ride (about 6 hours).

Saludos, MadridMan

Super information and many thanks! I think I got the wrong pull down menu or something because for some reason I just got the overnight train. I think I will take your suggestion and opt for the train...I love to take trains and Renfe looks like a really great train system.