A lot depends on the circuit. Watching the British Grand Prix from Becketts is spectacular for a while, but it's harder to follow the race because you only see the cars for a while. Meanwhile at Jerez, you can see large portions of the track from most vantage points. Following a race is easier at a track like that.
Those are the only two circuits I've seen Grands Prix at. Forever regretting not making the walk round to the back-straight stands for the 1997 European GP. Where I was was a good place to watch, but I missed the Villeneuve/Schumacher collision. Obviously I had no way of knowing that would happen, but I remember telling my parents that we'd probably see more overtaking there. In the end we decided on the stand on the inside of T8, opposite the chicane. We could see most of the "stadium" section behind the pits, and T1 in the distance.
(Tickets for that event were for each price bracket, (gold/silver/bronze stands) but you had a choice of which stand in your price backet to watch from. F1 wasn't all that popular in Spain back then.)
I'm reminded of a story my dad tells me from the 1987 Spanish GP. I was too young to attend. It was at the height of Mansell-mania, and the grandstands were basically full of British ex-pats. In the seats infront were a Spanish man and his young son. The stands would errupt in cheering whenever Nigel passed, on his way to a dominant win. Apparently at some point the boy asked "Dad, how's Adrian (Campos) doing?" to which the father angrily replied "Shut up boy!" (in Spanish of course).
You don't get stories like that when you watch in your living room.