With a launch TWR of 1.23 and a pretty good gravity turn, I got to a 125km orbit of Droo with 4848 m/s, according to the in-game dV calculator. I've not checked the craft with the Simple Engineer mod and I'm not sure if the in-game dV values are vacuum or atmo. I suspect they're vacuum which is fine by me, we always listed dV as vacuum in KSP too so I'm used to it.
Anyway, This makes 5000m/s a pretty reasonable (and nicely round) number to shoot for to get to orbit, when designing your craft.
@Aguis I've not played since making this post (I hate to say it but I prefer KSP, at least for now) but there are many factors that determine how much dV it takes to get to orbit, including the geometry of your gravity turn and the ratio of atmospheric and vacuum Isp of your engine(s), and what altitude you are while they're burning.
I optimized my launcher and gravity turn to get to orbit in an economical (on fuel) way, however if you optimize for raw dV you could end up doing it cheaper on dV with more fuel. Also, if you do not fly a good gravity turn or have vacuum-optimized engines deep in the atmosphere, you could have terrible dV numbers with a low-fuel rocket.
You can of course also get terrible dV numbers with a terribly high-massed and rocket, it's all in how it's designed and flown.