I will give it a crack

1. 300RUM (we know more is better)[&:]
2. 338RUM (and even more bigger better bang bang)
3. 300WSM (its new it has to be cool)
4..17HMR (All those 22's gathering dust now[])
5. 204 (cause its fast, and sticking with the more is better theme)
6. 300 SAUM (couldn't they come up with a snappier name)
7. 480 Ruger (continue on with the theme but can't forget pistols)
8. 460 Smith (and even more POWER) (guilty)
9. 500 Smith (No such thing as overkill, kills em deader than dead)
10. 45GAP (oh can't believe they were able to improve such a perfect round as the 45ACP, but somehow they pulled it out)
11. Five-seveN® (I mean you never know when you have to shoot thru body armor)[8D]
12. 6.8mm SPC (hard tax money at work)[:-]