x marks the spot/ aka scrappity do dah (I made this with a ton of completely different fabric and gave it as a gift. (the recipients loved it)
cathedral window
shadow box (this is awesome with different and patterned fabrics... the more different, the better)
I feel like if you get a good quality white fabric, you could make a ton of different quilts with radically different fabrics and the white breaks it up. You could even do a more traditional quilt like an Irish chain with radically different fabric.
tumbling blocks looks great. Just have to worry about color values, not about coordinating fabrics.
You can even do a sampler quilt and just use the sashing to break things up a bit.
Rail fence is easy and fun
Enjoy making the quilt. Don't be too critical. Once it is quilted, alot of the "mistakes" fade away. I don't make "perfect" quilts. I make them fun. I enjoy learning new techniques. I also decided that some things are too difficult or not fun for me to do. I shy away from: machine applique (tried, disliked), hand piecing and handquilting (did well but too time consuming for me), anything three dimensional like purses (frighteningly bad results), and Y seams (tried but difficult and not fun for me). You may love the things I dislike or visa versa. Try some stuff on smaller quilts. See what you like/dislike and stick with the fun stuff. Enjoy it. Once you have done a few quilts, it becomes alot easier and alot more fun.