Romy Schneider always will be Sissi to me, but not the Empress. I try to see them as something rather romanticized but lovely, I know Romy played the Empress one more time after the Sissi-Trilogy. She played her in the biopic on the life of Ludwig II of Bavaria called 'Ludwig', in that movie she plays a more true Elisabeth, she has quite a big part, as does her sister Sophie. I also have a miniseries based on the life of her sister Sophie. I have seen the BBC-series 'Fall of Eagles' wich features her too, also there is a miniseries based on the life of her son Rudolf, she is played there by Sandra Ceccarelli. I have also heared about 2 movie's based on her real life, Sisi und der Kaiserkuß & Sissi L'Imperatrice Rebelle - rather dramatised I've heared - , I have not seen both of the movies but i really want too, and there is also a musical based on her life called 'Elisabeth', it is a German production but I've seen parts of the dutch version, and soon I'll have a copy on dvd.
Here is my list with actresses I know that played her:
Romy Schneider(Sissi-Trilogy and Ludwig)
Vanessa Wagner(Sisi und der Kaiserkuß)
Arielle Dombasle (Sissi L'Imperatrice Rebelle)
Sandra Ceccarelli(The Crown Prince)
Pia Douwes(Elisabeth, The Musical)
Diane Keen(Fall of Eagles, Death Waltz)
Rachel Gurney(Fall of Eagles, Requiem for a Crown Prince)
I can try and get some screenshots of most of the listed productions, but Romy Schneider quite looked after the real Empress in my opinion. And as for who I'd like to see playing the Empress, well I haven't thought about it but I will and tell you who I'd like to see as the Empress when I post the pictures.