Quartus- here is my serious advice mate!! Don't simply sit back and ask others for their opinions. Go out there and use your ears and fingers to listen to and play the instruments yourself. We all have our biased and unbiased opinions to your very valid question and I will give you my opinions/suggestions below. But don't simply buy an instrument because someone else recommended it. That would be crazy!!!!
I myself really like the new Kurzweil 76 and 88 note stage pianos (with ribbon controllers to boot!). I'm not sure of their model numbers but they would probably be my 1st choice for a nice 88 key controller with inbuilt sounds.
I've also played the Yamaha S80. A great sounding sample based synthesizer with quite a nice action. However, it all depends whether you need all the other extra features. By the way you can already expand on the high quality sounds with up to 2 extra cards (one is a dedicated piano card!).
Check out the new Roland XV88 synthe (88 note weighted action) with D beam controller. I have got it's rack mount cousin (XV3080) on layby at the moment!!!!
Yamaha's P series pianos are nice (I've always liked them and the new P80 is nice.
Some criticise Korg's digital pianos, but I must say that the SG Pro X would be one of the 1st digital piano's I'd check out particularly for live work. Plus it has great organ and string sounds to boot! And it makes a nice controller keyboard as well.
The Korg Triton PROx with piano expansion board would also be a good option if you want an 88 key workstation.
Alesis QS8.1, check it out. However, I wouldn't go for this personally (that's not to say it's bad!).
Like I said above, USE YOUR EARS AND FINGERS and then make the final decision! Good Luck.