[Moogled]

Here's the best way to go about selecting livestock for a tank, IMO:

1. Search list of marine organisms on site such as liveaquaria.com

2. Choose all that catch your interest

3. Filter out your choice of organism.

4. Find compatibility in accordance to tankmates/ tank size.

You'll have to repeat 3 and 4 once in a while, and I find researching by yourself much better than asking people what you should keep. Reason being that fish are very subjective. Some people love Clowns but others don't want to keep cookie-cutter fish and would prefer something like a less common Goby of some sort.

25 gallons is fairly small, so you'll want to have 3 fish max, 4 if you're diligent in maintenance. A Royal Gramma is a good choice and gobies/blennies will definitely do well in a 25g.