For me, it really depends on where, the reason and the properties available.
But for business stays, HGI is my choice, as well as for some leisure stays. The brand has the most consistent offerings, and they are quite decent - room and amenities, breakfasts, etc. Homewood Suites comes in a close second for these.
For leisure stays, I often use Embassy Suites - more room, the living room "buffer" between the bedroom and the busy hallways, etc.
For leisure or celebratory stays overseas, Conrad is often my choice.
Doubletree fills in OK most of the time, and some have very good Park 'n' Fly rates - and they often treat Diamonds right. Doubletree Club - some are decent, some are barely marginal, the worst have been dismantled (notably MIA!).
Hampton fills the bill in some places HGI is too far away, and I pick and choose to avoid eating plastic effigies of fried eggs etc. A lot of variability at some of these.
Hilton... hmmm. That varies property by property. I like some, some are tired, some are not customer oriented at all. So, the "anchor" name brand seems the most variable - especially in the UK, I think - and I do my research beforfe booking (thanks, FT!)
W=A - hardly ever stay in 'em. Too much glitz, not enough bang for the buck.