Existen muchas maneras de expresar la sorpresa, algunas pertenecen al registro estándar o al popular:

¡Qué sorpresa!
¡Anda! (pop.)
¡Vaya! (pop.)
¡No me digas! (pop.)
¡Ángela María! (pop.)
¡Hombre! (pop.)
¡Mira tú por donde! (pop.)
¡Madre mía! (pop.)
¡Madre mía del amor hermoso! (pop.)
¡Ay, madre! (pop.)
¡Jesús! (pop.)a
¡Jesús, María y José! (pop.)a
¡Válgame Dios! (pop.)a
¡Dios! (pop.)a
¡Ay, Señor! (pop.)a
¡Dios mío de mi vida! (pop.)a
¡Hay que ver! (pop.)
¡No fastidies¡ (pop.)
¡Qué bárbaro! (pop.)

a Estas expresiones pueden no estar de acuerdo con el mandamiento religioso de "no pronunciar el nombre de Dios en vano", sin embargo, el hablante no las siente ni blasfemas ni ofensivas.
Pero otras son vulgaridades: usan referencias sexuales o religiosas. En negrita aparecen los sonidos que se alargan al pronunciarlos.

¡La hostia!
¡Ay va la hostia!
¡La hostia puta!
¡La puta!
¡No me jodas!
Muchos consideran estas formas muy groseras y prefieren utilizar eufemismos:

¡Caray! (eufemismo de carajo.)
¡Caramba! (eufemismo de carajo.)
¡Ostras! (eufemismo de hostia.)
¡Hosti! (eufemismo de hostia.)
¡Jolín! (eufemismo de joder.)
¡Jopé! (eufemismo de joder.)
¡Jopeta! (eufemismo de joder.)
¡Jodó! (eufemismo de joder.)
It is worth to consider that, as a difference with the English language, vualgarisms in Spanish are not so rude. For instance, the word fuck, which sounds strong in an English speaker is something that is common use in his spanish translation,Joder. So if you here some spaniard saying Joder all the time, it does not mean that is completely crap Emotion: big smile

By the way, the eufemisms our friend is posting seem to me to childish, I would see strange not to use joder and say jolines, jopeta.Emotion: smile
I´m with you anonymus, this is that i´m trying to explain in another post.

Thanks for explain it in english better than me.

Un saludo.
Well...., I don't know. It's relative. It's true that it is common to use expressions such as '¡me cago en la hostia!' or '¡joder!' in Spain but in some Latin American countries it may be considered very rude to use those expressions or their local equivalents. Of course, everybody swears but not that openly.
Nowadays, swearing has become much more common than it was a few years ago. I would have never dreamt of saying "Me cago en (whatever)" the way I see teenagers do now, when I was their age. I don't even dream of saying it now I'm in my thirties! So, now nobody but a child would use euphemisms such as "jopé", "jopete", "jolín" or "jolines". But I use "jolines", for example, and I don't feel specially childish.

"Mecachis" is another euphemism, this time for "me cago en..." There are a number of words you can use to complete the sentence. The strongest one would be "Dios" (God), but if we restric ourselves to euphemistic or humorous expressions, then we can say "la leche", "diez", "la mar", "todo lo que se mueve", "los moros" (although this one has always been used in a joking way, it could be considered racist nowadays), "la mar salada", and many, many more ("me cago en Windows" must be one of the most common expletives among us who work with computers). And one can always say "me cagüen to" (short funny version of "me cago en todo").

By the way, I think that those expressions labelled by MIkel with the superscript as possibly being at odds with the Commandments but not being considered blasphemous or offensive (with which I agree) are precisely used by pious people, mainly. People who don't care much about God don't use that kind of expressions (although they seem not to have any problem about using "me cago en ****"), and since atheists couldn't care less about God they don't use His name, either in vain or not.