Component.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OpenTK;

namespace FallingSpheres.Components
{
    public class Component
    {
        public override string ToString()
        {
            return this.GetType().Name;
        }
    }
}

Entity.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using FallingSpheres.Components;
using OpenTK;

namespace FallingSpheres.Entities
{
    class Entity
    {
        protected List<Component> Components = new List<Component>();

        public void AddComponent(Component inComponent)
        {
            Components.Add(inComponent);
        }

        public void RemoveComponent(Component inComponent)
        {
            Components.Remove(inComponent);
        }

        public Component GetComponent(string inTypeName)
        {
            return Components.FirstOrDefault(comp => comp.ToString() == inTypeName);
        }

        public virtual void Load() { }

        public virtual void Update(FrameEventArgs e) { }

        public virtual void Render() { }

        public virtual void Unload() { }
    }
}

Usage.cs

// LOADING //

// setup a sphere entity.
_sphereEnt = new Sphere();

// setup a model component for it.
Model model = new Model();
model.FromScene(AssetLoader.FromFile("couch1.obj"));

// setup a transform component for it.
Transform trans = new Transform();

_sphereEnt.AddComponent(model);
_sphereEnt.AddComponent(trans);


// UPDATING //
Transform referencedTrans = (Transform)_sphereEnt.GetComponent("Transform");
referencedTrans.Position += new Vector3(1, 0, 0);