Hmmm, I have many centerpieces in my 30g, but the real one would have to be my female honey gourami. She's just a little sweety, and all of the fish added to the tank since her are deeply close to her, as she'll follow them around with outstretched feelers and befriend new fish on sight.
If I had dream tanks, I'd have 2 5000 gallons in a mansion-like house, with a library, a history room, 1 living room with steering wheels and the SW tank, and the other with south american culture kind of thing with the FW tank there.
In the SW, there would be a dozen green, black, yellow, and citron clown gobies, and a dozen neon blue and neon yellow gobies, 50 sexy shrimp, 1000 dwarf hermits, 100 scarlet hermits, 100 zebra hermits, 20 emerald crabs, 20 asst. stars, 15 asst. sea cucumbers, 20 blue tuxedo urchins, 4 yellow tangs, 6 clowns, a few royal gramma and a load of other fish aswell
In the FW there would be 200 hatchets, lemon tetras, and pencilfish. There would be 300 neons, cardinals, rummynoses, glowlights, and those sparkling danio thingys. There would be a dozen male and 20 female dwarf gouramis, 20 male and 30 female honey gouramis, 40 sparkling gouramis, 80 dwarf neon rainbows, 2 dozen platies, 2 dozen guppies, etc, etc. :hearts:
My betta, Dante. He's showy, energetic, and fiesty... not like your usual American-bred bettas. He definitely commands attention when you see him in my planted fiver.
In my 10 gallon, since it only has the one fish, it'd be Lem. He's my elect. yellow cichlid. He's so cute chillin' in his little cave, moving the gravel around for a pretty girl that'll never show up... 
In my 30 gallon, Reptar's my baby. He's a 6 or 7" common sengal bichir. Loved him since I bought him as a wee little pinky finger-length baby from a store in Wal-Mart. He was being harassed by a CAE when I saw him. Now he'd probably have ate that lil' bugger for lunch!!!
But obviously he's going to continue to grow, so I'm gonna need something bigger than 30 soon or else my baby boy's gonna hafta find a new home. *sigh*
Btw Kyohti, that electric yellow should have atleast a 20 long...
3 angels in a 33 gallon tank (soon to be 38 gallon tank - I want the extra height).
Those angels should have a bit bigger tank, maybe a 50g or so... JMO..