Pepcid or Zantac
Demerol, yep it still has an indication or two (I do hate to give it though)
Cipro (some have went to Levaquin)
that ED standby "GI cocktail" Mylanta or Maalox + Donnatal + Lidocaine (sometimes - depends on patient/doc)
I think it can get a bit "overwhelming" when you think of all the drugs out there - remember, all hospitals have a formulary and there are "customary" meds that certain ED docs use. I think most of the universal drugs are listed - there will be variances.
I always advise that you can generally "pull" a list of stocked meds from the the ED's Pyxis or MedSelect or whatever system they use (some still use the open bin system (believe it or not) and only lock the narc's. The formulary is generally in the administrative/clinical reference manuals (or you can ask the pharmacy)
I think it essential to know the all the ACLS medications. Don't stress - it takes time/experience - look up any med that you have never given before - also use the pharmacy as a reference too.
After 15 years and 17 different systems/facilities (No, I don't job hop - staff, travel, prn) and find that I still will have to look things up or call the pharmacy from time to time.