I dont know how much i can give away due to copyright or something but anyway:
Chaos space marines - MEQS but spikey, and have champions with special weapon options

Plague marines - Expensive, great at absorbing fire and hard to kill + good special weapons
Nosie marines - Shooty shooty and shooty

Thousand sons - They are great very expensive champion with physcic powers
Bezerkers - Prettty cool guys with furious charge and rock in CC.
For 1.5kpts i'd go with:
2 squads of shooty units ( So regular, plague marines or noise marines)
and one CC squad, i'd go plague marines because they can hold there own.
Give each squad a rhino for added speed and mobility.
Honestly we can make a good fire army, my 1.5k and 2kpts list is kinda shooty
I go for this tactic:
I advance and use close range special weapons (i have around 15 melta-guns in my 2k pts list) and then charge whats left
EDIT:
http://www.40konline.com/index.php?topic=164405.0that is my 1.5kpts and 2kpts list, i'd advise getting the codex tho matey. It'll help get you started. Buy the codex before you buy any models and you can play around with lists etc...