i have had 2 s2k and like 6 dc5 (type-s ) wich is close to the type r dc5 and i like them both but if i have to choose i will pick the s2k because is just a sexy car suspension,wheels and hardtop and it looks like a super car...that is my opinion
You are talking about two very different cars here, so hard to tell what 'better' really means narrow it down slightly
In terms of Engine, I say S2000 wins, highly tuned factory output of 240-250bhp and solid high rev nature, it really needs no more praise.
In terms of chassis, THe DC5 chassis is refined but it has also put on more weight from the DC2, still a fine chassis and practicle. The S2k chassis has the high X bone frame and other finely crafted components makes it a great sports car and you wouldn't notice that it's a convertible. I think S2000 edges the DC5 slightly because of it's purity.
Brakes - DC5 has Brembo 4 pots, although saying that S2000 are useful. DC5 wins.
Looks - each to their own, hard say which is better. I prefer the look of the S2000 and some very good looking aftermarket bodykits as well.
I have no experience with either car but I would have an S2000 in a heartbeat. In fact, when I'm finished with uni and have a good job and somewhere to live I'll be taking a loan out and buying an S2000. I've wanted one since I first saw one.