Similarity Matrix

http://www.biomedcentral.com/1471-2164/8/353/figure/F5?highres=y
A similarity matrix does exactly what its name indicates: it uses colors to show whether (or not) data sets are similar to each other. Typically, darker colors are used to show a higher similarity between variables, while lighter colors are used to show just the opposite.
This similarity matrix shows the similarities between certain genes. Contrast pairs with significant similarity are coded dark red, while pairs with non-significant similarly have no coloring.

Correlation Matrix

http://aesop.rutgers.edu/~lamlab/chromatin/atepigenomics/atepigenomic.html
A corelation matrix assigns specific colors to each cell of the matrix, in an attempt to show a correlation between data sets. By adding color to the matrix, it is easier to see strengths and weaknesses, trends, patterns, etc. Correlation matrices are always symmetric.
This is a correlation matrix (on the right) that predicts the interactions between chromatin modifications through ANCORP analysis.

Parallel Coordinate Graph

http://servus.itn.liu.se/smartdoc/project_results/knowledge/MD-Viewer/summary.html
Parallel coordinate graphs are mainly used to show multivariate data, since they seem to be adapt at accurately conveying multiple sets of data. Each variable is graphed on a respective vertical axis while still exploring the relationship among the variables. This type of graph makes it easy to see trends while examining each individual variable.
The parallel coordinate graph above shows the values among several variables (mpg, weight, horsepower, etc.) that have to do with several vehicles.

Index Value Plot

http://waterwatch.usgs.gov/new/?m=real&r=nc&w=real%2Cplot
An index value plot is a visualization that compares the relativity of all values back to the index value (which is not an absolute value). The index value is plotted on the line graph as a straight line. All other values are thus plotted, and their proximity to the index value is analyzed.
This index value plot shows the average streamflow index for North Carolina for the last 45 days. The data was collected from mid February to the end of March.

Population Profile

http://camellia.shc.edu/literacy/tablesversion/assignments/statisticsassign.htm
A population profile is a chart that shows the number of people in a given city/area/state/country, according to their ages. The ages are often given in ranges of either 5 or 10, depending on the profiler's choice.
Above is the population profile for Mobile County, taken from the 1998 census data.

Triangular Plot

http://www.ex-parrot.com/~chris/wwwitter/20050407-it_doesnt_matter_how_you_vote_either_way_your_planet_is_doomed.html
A triangular plot (also called a ternary plot, ternary graph, or de Finetti diagram) is a barycentric plot on three variables, which all add up to a constant. Graphically, a triangular plot is depicted as an equilateral triangle, with the three points of the triangle representing the three variables. Basically, the proportions of the variables a, b, and c, all must sum to some constant K (which is represented as 1.0 or 100%).
The triangular plot above shows the outcome of a vote between Liberal Democrats, Conservatives, and Labours, due to a recent opinion poll.

Box Plot

http://itl.nist.gov/div898/handbook/eda/section3/boxplot.htm
A box plot (also known as a box-and-whiskers diagram) is a convenient way to categorize numerical data via their five number summaries: the smallest observation (sample minimum), lower quartile (Q1), median (Q2), upper quartile (Q3), and largest observation (sample maximum). Outliers may also be shown on a box plot. Box plots can be featured vertically, or horizontally. Box plots are generally used to show differences in population, but without making any assumptions.
The box plot above compares four machines for energy output.