First - SE Rhyno, if only to get them back into production. It's also the one disc in my bag that I trust with any shot.
Second - DX Teebird. It's my most reliable driver. Not a do-anything disc (it doesn't do sweep hyzers or big anhyzers well) and easy to turn and burn if you screw it up, but damn does it go straight.
Third and beyond - X Comet. I'm just getting back into this disc, but it is a Teebird for me but as a mid, and I love it for exactly the reasons set out in the preamble to the Comet Love thread at DGR (and re-posted here at least twice in our version). Everyone needs a disc that will go bullet straight.
I also like my old TP Cyclones, and if I can't get my DX Eagles to fly like a seasoned Cyclone's big S curve, I'm going back to the 'clones.
Traditional: Rhynos * Pure * Comets * Hornet * Leopard * Eagle * Teebird * Valkyrie * Firebird
150 Class: Rhyno * Hornet * Teebird * Eagle