My budget bottle of tequila right now is the Herencia Mexicana Blanco. Fragrant nose, floral tequila notes on the palate, very smooth and clean. At $20-$25 I think it's a pretty good value.
My favorite right now that I drink regularly is the ArteNom 1414. Just so effing good. Tons of flavor, dangerously drinkable.
Soon to try the other ArteNoms particularly the 1146 which I've heard great things about.
Got my eye on the TPS barrel strength Tequila Ocho bottling. Very interested in that one, but not sure if I'm $75+shipping interested just yet.
I recall liking Herencia Mexicana quite a bit and even have a bottle bunkered. Hi Time has it for $17.99. ArteNOM's entire line is fantastic. I think that I like the 1414 the best too, but the 1146 anejo is really good.
For $75, get the Corrido Anejo - $40 & Reposado - $35 (Also at www.hitimewine.net) if you haven't had them. Some of the best tequila for the money that's out there right now. I'd recommend the Crotalo line too...the anejo expecially.