I was gonna leave it up to other people lol, but I guess now you've forced me into it. Prepare to read more into it than anyone ever expected possible.
As a beginner, I'd say that despite the price, either ICS L85, or an ICS M4 would be a good place to start. The ICS L85 is a fantastic gun, very easy to strip down, very easy to work on, very easy to upgrade, albeit with limitations.
The ICS M4s have a special "split" gearbox which makes them easier to work on, and they have practically the same upgradability as any other M4, aside from things like different body kits and stuff, which isn't something that really bothers me anyway. You can still slap rails and optics, lights, lasers whatever on them.
So it's up to you. They both go for around £300, though you can get the plastic M4s for around £190 and up I think. Or other, metal M4s for around the £240 mark.
I'd say the major pros the L85 has is the ease of take down, getting to the gearbox is a breeze, and you can adjust the power of the spring, and even replace the whole spring in under a minute once you get the hang of it, so you can have it shooting sweet for any site you might want to go to. You don't even need any tools. Spare parts are easy as pie to come by, not that you need to look at it much, and as testament to how great they are, I'd never opened up a gun before I got my ICS L85, now I've learned everything I know about electric guns from it and got it shooting like a beast.
Bad things about the L85? The weight, it's getting on for 5kg, which hits you like a brick if you're not used to it. The bullpup config means that the entire weight tends to be on your right arm the entire time as well, there isn't really a way you can hold it to take the weight off with your other arm. Get a sling.
The sights are raised quite a way above the barrel, making it quite hard to aim over cover without exposing a hell of a lot of yourself.
Aiming over cover is an issue compounded by the fact that it's hard to aim and shoot instinctively, by which I mean, if you see someone and don't have time to aim, it's hard to point and shoot at them using instinct alone. Reason being, you're holding it by a grip which is mid way down the barrel, there's as much gun behind your hand as ahead of it. It's sort of like aiming a massively unbalanced pistol. You'd have to try it to know what I mean, but the more gun there is infront of your hand, the easier it is to point at things. So despite having a longer barrel, when it comes to snap shooting the M4 still has the upper hand, it's just much easier to point and shoot an M4.
When it comes to aimed fire though, the L85 is much easier to support, you have more body contact with the rifle, it's comfortable, can't go wrong. Especially with a few upgrades.
Practice makes perfect though, and a lot of the time the difference these points makes is negligible. They're hardly the kinda things you have on your mind when you're running about shooting people and getting shot at.
I don't notice any of the cons so much anymore aside from the raised sights issue.
M4s are the most modular guns around, can be bought for around £100 less than the L85 and are probably on the whole better performers. I think L85s are just more sexy though.

Do I get bonus points for showing off a forum patch? They're cheap, you should all get some!