I kind of have a thing for Nurgle Marines lately and I have been slowly working on building up an army of my own. I fully intend my Nurgle marines to be my primary tournament army and as such I am building the army up with units that are less often used but offer unique tactical options. One thing I should note is that in my area Sportsmanship is the most important aspect of the game, we are not super competitive around here and we focus on having fun before smashing face. So two units I have fallen in love with lately are Havocs and Nurgle Bikers.
Now when most people think of havocs they think of a heavy weapons team that sits back and shoots from afar. What I have in mind is a unit of five havocs in a rhino with 4 flamers. I am currently in the process of building this unit but the strategy I have decided on using with them is a bit of what I call Tank herding. With nids making their way to the tournament scene an anti-horde unit is much needed in my army. My army is designed to be purposely outnumbered and so the flamer unit will be a boon. So what I do with these guys is keep them inside their rhino and work on getting them in position for a tank shock. So the plan is to tank shock a unit and herd them into one big mass on the forward left or right of the rhino in such a way that my havocs will be able to deploy and open fire on the massed unit getting as many hits as possible. It shouldn't be too hard at all to score upwards of 30+ hits this way on a 10-20 man unit. The main thing that drew me to this particular unit for this job (as apposed to chosen who could pull this same strategy off just as effectively) is that they are relatively cheap and very good at what they do. for 130 points you have a serious threat that is not only mobile but easily under appreciated by the enemy. They are very easy for the enemy to skim over when they are examining your list especially if they have never seen the unit used this way. I've yet to put it to the test but I will most certainly give you some battle reports with it once I get to it.
So another unit I have a lot of fun with is Nurgle bikers. They are expensive I admit, but they are the whole reason I started playing Chaos marines in the first place, there is just something about a super fast super tough unit that draws me in. So the first thing I would like to point out about these guys is that there is no good weapon to use on them. I figured I would run down a list of weapons and how many shots it would take to cause just one unsaved wound.
Lasgun: 1Kill=3 wounds (3+ Armor)=18 hits (6 to wound)= 36 shots (4+ to hit)
Bolter: 1Kill=3 wounds (3+ Armor)=18 hits (6 to wound)= 27 shots (3+ to hit)
Heavy Bolter: 1Kill=3 wounds (3+ Armor)=9 hits (5+ to wound)= 13-14 [13.5]shots (3+ to hit)
Scatterlaser: 1Kill=3 wounds (3+ Armor)=6 hits (4+ to wound)= 12 shots (4+ to hit)
Starcannnon: 1Kill=3 wounds (3+ cover)=6 hits (4+ to wound)= 12 shots (4+ to hit)
Starcannnon: 1Kill=3 wounds (3+ cover)=6 hits (4+ to wound)= 9 shots (3+ to hit)
Plasma: 1Kill=3 wounds (3+ cover)=4-5 [4.5] hits (3+ to wound)= 6-7 [6.75] shots (3+ to hit)
Melta: 1Kill=3 wounds (3+ cover)=3-4 [3.6]hits (2+ to wound)= 5-6 [5.4]shots (3+ to hit)
Lascannon: 1Kill=3 wounds (3+ cover)=3-4 [3.6]hits (2+ to wound)= 5-6 [5.4]shots (3+ to hit)
Looking at this list it would appear that the best option on the list would be a plasma gun (due to the ability to double tap) but even then it is going to take the commitment of 3-4 plasma guns to shoot down just one biker. But what that does for you is keep shots off of your Daemon princes and rhinos or whatever high priority units you have heading towards the enemy. You also want the opponent firing their lascannnons and meltas at this unit and away from your landraiders and predators and what have you.
Long story short, you equip this unit with high threat weapons (I go for either melta or plasma) something you know is going to draw the opponent's attention and turbo-boost right at what your target is (monstrous creatures, vehicles something important) while you move your primary threats into position. It is a lose lose lose situation for the opponent. Either the opponent commits too much fire at the unit drawing fire away from your main force, or the opponent ignores them for the juicier target then loses whatever your target is, or the opponent assaults the unit and gets tarpitted for the rest of the game. Just whatever you do do not put the unit in assault range of power fist/ thunder hammer units that is just bad generalship.
The most important thing about this unit is it's high mobility, it makes a great tarpit and an excellent back field hunter. It's distraction and late game contesting. It just does everything despite it's high cost. Sure you are going to blow more on this unit then you would a land raider but for this level of flexibility it is worth the cost.
That's all I have for now come back later for more fun unit tactics and remember, while winning is certainly fun it's not everything. Try a unit out that you wouldn't normally take. you'd be surprised at what you could do with it if you just think outside the box.