There are so many choices. Where to start...
If you are interested in gay literature then I recommend Holding the Man by Timothy Cosgrove. Beware that the second half had me crying during parts of it. So take large sunglasses with you to hide the tears if you are going to read this in public.
Other recommendations are: John Irving's Until I Find You or A Prayer for Owen Meany, Anything by Tom Robbins (his stories are a bit wacky, but fun and good beach reading), Khaled Hosseini's 2nd novel A Thousand Splendid Suns (his follow-up but not sequel to Kite Runner - I think ATSS is better than Kite Runner).
And if ever in doubt pick up a classic like Frankenstein, Old Man and the Sea, Of Mice and Men, Jayne Eyre or Emma. The classics are littered with great reading.
Anyhow, hope this helps narrow the field. Enjoy your summer reading.