I think they all look really good but personally my favorite is the second one down.
I think with CCTV cameras being grey etc it looks more fitting. Also that grey has a nice sinister feel about it.
I think the pink contradicts with the background images.
The AV of AVIOD needs to be made clearer and the word Link is slightly hard to read.
regards
Richard
Network Freelance - PR and Marketing Contracts
Provident Home Buyers - Quick House Purchases
Commercial Lease Back - Property Buyers