Asics are a decent trail shoe and usually reasonably priced. Another vote for a Brooks Cascsdia as a solid choice.
But the best trail shoes by far for quality a La Sportiva, although they are expensive. The La Sportiva Bushido is the finest quality trail shoe I've ever worn, but possibly too aggressive for some. It borders on being a mountain shoe, although i wouldnt wear it on a full-on Fell Race in poor conditions here in the UK.
The Bushido doesn't have much cushioning though, and if this is an issue then the Akasha is a fantastic alternative. A lot more cushioning and the grip is equally good (although again I wouldnt risk on a Fell Race in the UK). I currently use these for all my training(trail, track, road, grass). I am loathe to go for full road shoes, as when I race (mountain/fell) I use shoes with little or no cushioning, and the shock of going from regular road shoes to pure Fell shoes would be too much.
That said I'll be going back to the excellent Bushidos for my next purchase.
