(This is Marcy, my rat. She is, alas, no more.)
Given that preference, it's really a wonder that Skaven were my 4th WHFB army (not counting a few smaller projects). I find it really interesting that they're in the current starter set- I would not call them a beginner's army in any sense. With huge numbers of models, highly unpredictable (if high-powered) units, and wildly unstable leadership, they have incredible potential for both victory and frustration. But hey, if it means I can get models cheaply from players buying Island of Blood for the High Elves (Thanks Emily!), it works for me.
I built and painted my Skaven force in the waning days of 7th edition, with the last edition of the Skaven army book. The Skryre Army of Doom was the strongest build, but I couldn't resist a horde of Clanrats and Slaves, marching along with the Screaming Bell. With the old Mainstay rule, my force was built in chunks based on the Clanrat units- 25 Clanrats, 20 Slaves, 20 Plague Monks, wash and repeat.
The update to the Skaven book changed that quite a bit. For one, the Screaming Bell changed size dramatically, making my Stormvermin unit suddenly rather the wrong size, and the power level of the weapon teams swung drastically away from the Ratling Gun (the obvious choice previously). Clearly something had to be done, but I let the army sit for a bit, as I was working hard on getting my Dwarfs to a relatively finished state.
Enter 8th Edition. With so many advantages to large units of infantry, the Clanrats started to look better and better, and my old list with it's 25-rat blocks started looking just a little bit inadequate. After getting my hands on the Skaven from the Island of Blood, I finally had the motivation to look through my collection and figure out how the force would work.
First to go was the relatively tiny Clanrat units. With plenty of spare models in the bitz box, it was a simple matter to combine them into a 50-strong unit with spears. Running in 10-wide Horde formation, the first four ranks get to fight, and dropping a Warlord in the unit gets them to Leadership 10 with room to take a few casualties without losing effectiveness. The two smaller units of Clanrats get a role protecting the flanks of the big monster unit.
The Plague Monks didn't have a whole lot to change- the new army book gives them two hand weapons by default, which is what I had built mine with, it was just a matter of adding more models to the unit. 25 should be enough, at least until I build a Plague Furnace.
The Skavenslaves get no help. Nay, they DESERVE no help! Intended as a discount speedbump, I don't know how to improve on 20 models for 40 points, except by churning out a couple more units of the poor guys. Nothing like getting them into combat in order to hold a target in place for shooting. Life is cheap, especially at 2 points per model.
The Stormvermin are a bit of a conundrum. I need to get my hands on some more of the old models- 19 just isn't enough to hack it, and the new figures, while beautiful, don't match up well visually. I have re-based my Screaming Bell, but without the Stormvermin to push it, I think I'm going to stick with a Warlord as my general for a little while.
Ah, the Weird Stuff, the reason to play the Skaven in the first place. Island of Blood comes with some killer Rat Ogres, not to mention the only available model for the Plague Mortar. I also have a stack of Poison Wind Globardiers and Plague Censer Bearers from the Warhammer 25th Anniversary box. The right mix of weird stuff, of course, can define the character of the army. At the moment, I'm leaning towards a Warpfire Thrower with the big unit, though I am seriously considering picking up a Doom Flayer for maximum smashiness. The other units are currently getting Ratling Guns still, since I have them around, but I will likely be switching them out for Warpfire Throwers. The Warp Lightning Cannon is less overtly bizarre than it used to be, but it still certainly merits a spot in the list.
A horde gets nowhere without someone to lead it, even someone as conniving and cowardly as a Skaven general. The Skaven line was hurting for cool looking characters when I got started, but the Island of Blood solved that problem rather nicely with a fantastic looking warlord. My old Warlord model will now be doing BSB duty, and with Ikit Klaw back in the army list, I'll be using a regular Engineer for my pistol-shootin', lightning zappin' duties.
Overall, I think the new army book is a vast improvement, and with a couple of players spinning up WHFB armies right now, it's a good time for me to stop resting on my Dwarfy laurels and get to painting again. The original Clanrats and slaves are some of the most effective and easiest models I've painted- once I fire up the spraygun, I'll take some step-by-step shots.