My favourite subject.
Personally I'm not really fussed about whether or not we have a 'custom kit'. My preference is always a fairly simple blue shirt, white shorts, and white socks of course - if you look here you'll see we haven't had that since 1980 (41 years ago!). Just once I'd love for us to get a blue shirt that doesn't have loads of unnecessary white or yellow flashes and lines and stripes all over it.
I still say that for this season we should have gone with a modern remake of this design to celebrate the 50th anniversary of our 1971/72 European run...
My favourite from more recent years is the 2014 Cup Final kit, or the one we wore during the 2013/14 season. Both fairly simple designs without too much going on. I also really liked our 2003/04 kit, even though it reminds me of one of the least enjoyable seasons I've ever endured.
I agree with you when it comes to away kits, though. We should go crazy with the away kit - do something completely out there that gets noticed. That's why people still talk about the teal and magenta kit. The further from boring white or yellow the better, at least for a couple of years.