Hah. I think I am in the same boat regards the whole top 5/10/20 thing. The conversation last night kinda sums that up. I've seen so many things, many of them good (as I tried to filter out a lot of stuff that wasn't so good before I watched it, or an episode or two in); that trying to definitively give a top XX is just impossible as it varies dependant on my mood. Toradora and Spice and Wolf are the only ones that are consistently in every list I do, simply as I think both are sublime, and there is a massive sweet spot in my heart. (There is a canvas wall art from the series sitting behind me right now, although it'll be going back into storage once my family finishing moving as I don't have anywhere to display it right now). Planetes is another that just came to mind, genuinely fantastic but completely forgot it yesterday.
I watched Ergo Proxy years ago; it's interesting but I was never as fond of it as others at the time seemed to be.
One on my imminent 'To Watch' (as I am clearing a load of older discs) is Cowboy Bebop, never properly watched it (I know, I know, it just never quite happened!), and given I have the discs sitting there, and the Netflix adaptation just came out; now seems as as good a time as any to watch it and the adaptation and see how I feel it's aged etc. I think its one or two shows further in my disc selection.
Just finished House of Five Leaves in a little spare time this morning; the art style is interesting; the show I guess I can think of I could compare it to most would probably be maybe Katanagatari, BUT it's not really like that either. Very interesting show though that slowly spells out it's plot. Not a top tenner, and one I probably won't watch again, but I'm glad I watched it. It's an old BEEZ release so kinda sums up how long I'd had it sat around; they went out of business roughly a decade ago.