I like large, readable fonts, and I generally use one of two Bibles.
One of them is on sale right now for $25.00
at bible.org. Each pair of pages has the Nestle Aland 27th edition on one side, with the full apparatus, and the NET translation on the other side, with really good translator's footnotes. I like the footnotes better than the translation. You can see a pair of facing pages
here, and a sample of the features of the English pages and appendices
here. I like this edition when I want to know various ways a passage has been translated, the textual basis for a passage, and all that scholarly head stuff.
The other GNT I use a lot is the Greek Orthodox Patriarchal Edition 1904, available at the
Bob Jones Campus Bookstore thanks to Randy Leedy, a professor who makes them available, and otherwise hard to find in the United States. It's just the text, without apparatus or translations or notes. It comes in two sizes, the smaller size is hard for my eyes to read in long settings but fits in a shirt pocket, the larger size is very easy to read but still small enough to carry very conveniently. And a great advantage of this edition is that you can download free MP3 recordings read by a native Greek, an Orthodox monk who reads very well. I have them on my MP3 player, and listen as I read. You can find these recordings and other tips
here. I like this edition when I really want to read Greek.
ἐξίσταντο δὲ πάντες καὶ διηποροῦντο, ἄλλος πρὸς ἄλλον λέγοντες, τί θέλει τοῦτο εἶναι;