This is a great addition to your arduino projects from Inventr.io is the 37-in-1-sensor-kit  .   Below I went and separated them into Analog and Digital sensors.

 analog
[KY-013] Analog Temp
[KY-023] Joystick
[KY-026] Flame Sensor
[KY-039] Heartbeat Sensor
[KY-024] Linear Hall
[KY-037] Big Sound Sensor
[KY-036] Touch Sensor
[KY-018] Photoresistor
[KY-025] Reed switch
[KY-035] Analog Hall Sensor

digital
[KY-016] RGB LED
[KY-027] Light Cup
[KY-003] Hall Magnetic Sensor
[KY-019] Relay
[KY-009] SMD RGB
[KY-017] Tilt Switch
[KY-001] Temp
[KY-011] Two Color LED
[KY-008] Laser
[KY-020] Ball Switch
[KY-038] Small Sound Sensor
[KY-028] Digital Temp
[KY-004] Button
[KY-033] Tracking
[KY-012] Buzzer
[KY-002] Shock Sensor
[KY-015] Temp and Humidity Sensor
[KY-022] IR Receiver
[KY-032] Avoidance Tracking
[KY-040] Rotary Encoder
[KY-031] Tap Sensor
[KY-029] Mini Two Color LED
[KY-010] Light Blocking
[KY-005] IR Emission
[KY-006] Passive Buzzer
[KY-021] Mini Reed
[KY-034] 7 Color Flash

This is a breakout board for the very handy 16-Channel Analog/Digital Multiplexer/Demultiplexer CD74HC4067. This chip is like a rotary switch – it internally routes the common pin (COM in the schematic, SIG on the board) to one of 16 channel pins (CHANxx). It works with both digital and analog signals (the voltage can’t be higher than VCC), and the connections function in either direction. To control it, connect 4 digital outputs to the chip’s address select pins (S0-S3), and send it the binary address of the channel you want (see the datasheet for details). This allows you to connect up to 16 sensors to your system using only 5 pins!

I don’t like many wiring going back to the Arduino.   I use shift registers to accomplish this.  Now, I found this 16 channel Analog to Digital MUX that can display 16 analog devices on 5 wires.   You have SIG going to A0.   You have S0 to S3 going to 4 digital pins for the logic table for channel 0 ( 0 – 0 – 0 – 0) to chanell 15 ( 1-1-1-1).