civic vs...?

i currently have a 96 civic dx (not racing it LOL) but i am getting a new car within the year and i was wondering which would be a better pick reliablity and speed.. either a newer civic si, eclipse gsx, 300zx, 240sx all i really know about is civics since i own one but i was just wondering if anyone who has any of those cars would tell me any problems or just what they think.